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PALHONTOGRAPHICAL SOCIETY.

INSTITUTED MDCCCXLVIT.

LONDON:

mMbDCCcCCIV—MDCccccxIIl.

MONOGRAPH OF THE CRETACEOUS LAMELLIBRANCHTA
OF ENGLAND.

VOL. Et

ORDER OF BINDING AND DATES OF PUBLICATION

PAGES PLATES ae See PUBLISHED
General Title-page and Contents ~- 1912 February, 1913
1—56 I—VII 1904 December, 1904
57—96 VIII—XI 1905 November, 1905
97—132 XTI—XIX 1906 December, 1906
133—180 XX—XXVII 1907 December, 1907
181—216 XXVITI—XXXIV 1908 December, 1908
217—260 XXXV—XLIV 1909 December, 1909
261—284. XLV—L 1910 January, 1911
285—340 LI—LIV 1911 February, 1912
341—473 LV—LXII 1912 February, 1913

we A MONOGRAPH

OF THE

CRETACKOUS LAMELLIBRANCHIA

ENGLAND.

BY

HENRY WOODS, M.A.,

UNIVERSITY LECTURER IN PALHZOZOOLOGY, CAMBRIDGE.

(Obey 10 ATION

LONDON:
PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY.
1904—1913.

P | } vi
PRINTED BY ADLARD AND SON, LONDON AND aes 7

Ostrea ...

Exogyra

Lima cs
» (Plagiostoma)
» (Acesta)
» (Mantellum)
, (Ctenoides)...
» (Limatula) ...
, (Limea)

Pteria (Oxytoma)
» (Pseudoptera)
Aucella ...
Aucellina
Gervillia
Perna
Tnoceramus
Pinna -...
Astarte... oa
» (Hriphyla)
Opis a
Cardita ...
Crassatellites
Anthonya
Cyprina...
Trapezium
Tsocardia
Lucina ..
Corbicella
Sphera...
Mutiella
Unicardium
Thetironia
Tellina ... nar
» (Paleomeera)
», (Linearia)
Mactra ..
Ptychomya

CONTENTS

OF VOR:

IE

72

74, 425

87

262, 433

96

102

113, 426
118

121

128, 426
130, 426
131, 427
148

151

152

157

157

160

162, 428

165

171, 429

173
175
177
179

vi CRETACEOUS LAMELLIBRANCHIA.

PAGE
Dosiniopsis rs <- tae sts at ae 181
Cyprimeria (Cyclorisma) _.. * ; re yy oe Ls 183, 431
Clementia (Flaventia) ne : “ok ey aes ee es 189
Callista ... = é ex ax iy Ar Ris a a 192
Tapes (Icanotia) ... a Ss saa xy bee san 431
Protocardia ry rd ve re ay BS a Xs: or 194.
Cardium i, Efe as ee 18 aes sm we ae 201

> (Granocardium ) ; a Ree re ee rr Pe 205
Toucasia es ae £. st ee a “Sy ar 207
Gyropleura ns : ws ; ne a at bos 208
Durania... A re ee Aa ae ae etn . + 420
Corbula ie ee Ny es tp ae CO on a 210
Pharus ... ae e. ae 4 ys Af ye ee oh 217
Solecurtus (Azor ?) Bet oes Be Pa as =e see ae 218
Leptosolen a ee * os ae sf te. es 219, 4382
Panopea at ae ire us “fis ae a a 221
Martesia <. se e is me ste aoe ne Be 231
Turnus ... 5% re ee aa < 59 233
Teredo ... x Bs Ate ae a6 Pee Sen - 237
Plectomya AS: £ abe dee ot no Ben es eee 238
Anatina (Cercomya) as oe ss a neh 50 see oe 238
Thracia ... Pr . ve a or Bs 208 ae 240, 432
Pholadomya eA, a a = =r =f ae bck ee 245
Myopholas * oe es ss si aes a ae ee 253
Goniomya te re ae Sn Yo one <i eras os 254
Pleuromya ear =A F 2 ae e < sr 256
Liopistha (Psilomya) can soe oes se at 3 se es 257
Cuspidaria oF Sy “fi ee ate se om A ne 259
Additions and Corrections ae eRe ae oe sae a ec 423
Tables of Distribution “ oo sae Si = sat a _ 434
Bibliography A ae ae se ots at 3s me ss 449
Index .. Fr m te we Sn 50 ae ae 462

THE

PALAAONTOGRAPHICAL SOCIETY.

INSTITUTED MDCCCXLVII.

VOLUME FOR 1904.

LONDON:

MDCCCCIV.

A MONOGRAPH

CRETACKOUS LAMELLIBRANCHIA

ENGLAND.

BY

HENRY WOODS, M.A.
UNIVERSITY LECTURER IN PALZOZOOLOGY, CAMBRIDGE,

VO PART I
LIMIDA.

Paces 1—56; Prares I—VII.

LONDON:
PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY
1904.

DESCRIPTION OF SPECIES.

—

Family—LIMIDA, @ Orbigny.

Genus—Lima, J. G. Bruguiere, 1797.

(‘ Encye. méthod.,’ Tabl. Vers., pl. cevi.)

Lima canauiera, Goldfuss, 1836. Plate I.

bis ©]

1836.
1839.

Lima canauirera, A. Goldfuss. Petref. Germ., vol. ii, p. 89, pl. civ, fig. 1.

-— H. B. Geinitz. Char. d. Schicht. u. Petref. des sichs.
Kreidegeb., pt. i, p. 24.
MULTICOSTATA, Geinitz. Ibid., p. 24, pl. viii, fig. 3.
CANALIFERA, F'. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p. 56.
LATicosta, Rémer. Ibid., p. 57, pl. vin, fig. 9.
muuticostatTa, H. B. Geinitz. Die Verstein. von Kieslingswalda, p. 23,
pl. vi, fig. 10.
Laticosta, A. EH. Reuss. Die Verstein. der bohm. Kreideformat.,
pt. 2, p. 34.
mMuLTicosTaTa, Reuss. Ibid., p. 34, pl. xxxviii, figs. 7, 8, 18.
_- H. B. Geinitz. Grundr. d. Verstein., p. 472.
CANALIFERA, Geinitz. Das Quadersandst. oder Kreidegeb. in Deutsch-
land, p. 190.
MULTICosTATA, Geinitz. Ibid., p. 192.
CANALIFERA, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 167.
MuxLtTicostata, d’Orbigny. Ibid., p. 248.
Laticosra, d’Orbigny. Ibid., p. 249.
CANALIFERA, A. Kunth. Zeitschr. d. deutsch. geol. Gesellsch., vol. xv,
p- 726.
— R. Drescher. Ibid., vol. xv, p. 356.
muuticostata, 2. Hichwald. Letheea Rossica, vol. ii, p. 459.
muuticosta, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5), p. 174.
CANALIFERA, Pictet and Campiche. Ibid., p. 175.
—_— H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleon-
tographica, vol. xx, pt. 2), p. 38,
pl. ix, figs. 6-—8.

2 CRETACEOUS LAMELLIBRANCHIA.

1876. Lima cananirera, D. Brauns. Zeitschr. f. d. gesammt. Naturwiss., vol. xlvi,
p. 386.

1877. — = A, Fritsch. Stud. im Gebiete der bohm. Kreideformat. :
II, Weissenberg. u. Malnitz. Schicht.,
p. 132, fig. 117.

1893. — ef. canatirera, R. Michael. Zeitschr. der deutsch. geol. Gesellsch.,
vol. xlv, p. 242.
1898. — cananirera, G. Miller. Mollusk. Untersenon. v. Braunschweig u.

Ilsede (Abhandl. d. k. preussisch. geol.
Landesanst. N.F., Heft 25), p. 28.
1901. — — H, Imkeller. Wreidebild. am Stallauer Eck (Palzeon-
tographica, vol. xlviii), p. 32, pl. iii, fig. 10.
— — _ F. Sturm. Jahrb. d. k. preussisch. geol. Landesanst.
fiir 1900, vol. xxi, p. 90.

Description.—Shell moderately convex, oval or subtriangular ; height a little
ereater than length; outline rounded, except the antero-dorsal margin, which is
nearly straight and rather long. Apical angle from 105° to 110°. Umbones
rather small, close together. Anterior area slightly depressed, with small radial
ribs. Anterior ears small; posterior larger, with growth-lines and faint radial
ribs.

Ornamentation consists usually of 18, but sometimes of as few as 14 or as many
as 21 very strong, rounded, straight ribs, which are separated by broader furrows.
In well-preserved specimens numerous concentric lnear ridges occur on both ribs
and furrows, and projecting growth-ridges are seen at regular intervals on the

ribs.
Measurements :
(1) (2) (3) (4) (5)
Length 2 70... 86 925 52.05, 43°F se2amnrne
Height’ . COM ae POS), ees 44. S85,

(1—5) Upper Greensand, Ventnor.

Ajjinities—An exact comparison of the English specimens with the foreign
examples of Lin canalifera is rendered difficult owing to the fact that the former
have the shell well preserved whilst the latter occur chiefly as casts. In both
cases the number and breadth of the ribs show considerable variation. The fine
concentric ornamentation is the same in both, as is shown by Goldfuss’ figure, but
in some of the best preserved English specimens there occur also transverse
ridges on the ribs at regular intervals. Somewhat similar ridges are shown in
Goldfuss’ figure, but they seem to be present chiefly on the sides of the ribs and

1 In all species of Lima (unless otherwise stated) this is measured obliquely to the hinge-line so

as to give the greatest height.

_

LIMA. 3

in the neighbourhood of the umbo only. With the exception of this character the
English specimens agree closely with the foreign examples, and this difference
may very well be due to the latter being much less perfectly preserved than the
former. Moreover, in some English specimens the ridges mentioned are partly or
entirely wanting.

The English examples occur at a lower horizon than those found abroad,
namely, in the zone of Pecten asper. The foreign specimens are found in the
Turonian and Senonian, and possibly also in the Cenomanian, and, like the English
examples, they occur chiefly in beds of a sandy nature. This last fact may account
for the absence of the species in the English Chalk, during the deposition of which
the sea-floor was formed of ooze and was at a greater depth.

Lima Htalloni, Pictet and Campiche,' from the Valanginian, presents some
resemblance to L. canalifera, but has a smaller apical angle; the character of its
fine ornamentation is unknown.

T'ype.—Goldfuss’ specimens came from the Senonian of Quedlinbure, Haltern
and Regensburg.

Distribution.—Upper Greensand (zone of Pecten asper) of Ventnor.

Lota Gatirennet, d@ Orbiqny, 1847. Plate II, figs. la—e.

1847. Lima Ganurenntana, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 548,
pl. eecexx, figs. 1—3 (Galliennei on

plate).

1850. — — — Prodr. de Pal., vol. 11, p. 166.

1854. — Gauuiennet, J. Morris. Cat. Brit. Foss., ed. 2, p. 171.

1867. — ~ E. Guéranger. Album Paléont. de la Sarthe, p. 18,

pl. xxiii, figs. 23, 24.

1869. — _ F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Mat¢r. Pal. Suisse, ser. 5),
p. 168.

1871. Raputa GALLIENNE!, F’. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. ili, p. 414.

Deseription—Shell compressed, more or less oblong with rounded margin ;
height greater than length. Antero-dorsal margin straight or slightly concave.
Apical angle large. Umbones close together. Anterior area only slightly depressed,
with sharp borders.

Ornamentation consists of 12 to 15 strong, much elevated rmbs with rounded

1 «Terr. Crét. Ste. Croix’ (1869), p. 141, pl. elxiv, fig. 3.

4 CRETACEOUS LAMELLIBRANCHIA.

summits, separated by broader rounded furrows. Both midges and furrows bear
numerous flattened radial ridges separated by linear grooves; the ridges, in
well-preserved specimens, are serrate or granular. At distant intervals a few
well-marked growth-ridges occur.

Measurements :

(1) (2)
Length ; 49 : 70 mm.
Height , 5A : ihc he

(1, 2) Upper Greensand, Devizes.

Affinities —This species is distinguished from L. canalifera (p. 1) by the
ralves being more compressed, the ribs fewer in number, the grooves relatively
broader, and by the presence of fine radial ornamentation on the ribs and grooves.

Remarls.—This appears to be a rare species in England. The specimens from
Devizes are in the Museum of Practical Geology. The specimen from Humble
Rocks was collected by Mr. Jukes-Browne, and is now in the Sedgwick Museum.

T'ype.—From the Cenomanian of Coudrecieux, Sarthe.

Distribution—Upper Greensand (zone of Schlanbachia rostrata) of Devizes.
Base of Chalk Marl (Bed 10) of Humble Rocks, West of Lyme Regis.

LIMA VECTENSIS, sp. nov. Plate II, figs. 2, a—c.

Description Shell large, rather compressed, ovate, height greater than length ;
antero-dorsal margin straight, the remainder forming a regular curve. Anterior
area deeply depressed. Apical angle apparently about 100°. Anterior ear small ;
posterior ear larger, with a few ribs.

Ornamentation consists of about 40 rather strong, narrow ribs, with rounded
summits which, in places, are slightly tubercular. The ribs are closer together on
the anterior part of the valves than elsewhere. The interspaces are much broader
than the ribs, and are flat or slightly concave; they are marked by numerous fine,
concentric ridges.

Affinities —This species resembles Lima Dujardini, Deshayes,' from the
Senonian, but the interspaces are flat or nearly flat instead of concave, and the
well-marked scale-like projections which, in L. Dujardini, are placed at intervals
on the ribs, but without a concentric arrangement, are not seen.

1 Dujardin, ‘Mém. Soe. géol. de France,’ vol. ii (1837), p. 227, pl. xvi, fig. 8.. D’Orbigny, ‘ Terr,
Crét.,’ vol. iii (1847), p. 569, pl. cecexxvii, figs. 1—4.

LIMA. 5

Remarks.—I have seen one example only; it consists of both valves, but with
the posterior margin imperfect.

Type.—In the Museum of the Ventnor Institute.

Distribution —Upper Greensand, chert beds (zone of Pecten asper) of the Isle

of Wight.

Lrma supovatis, Sowerby, 1836. Plate IT, figs. 3, 4a, b, 5a, b, 6a, b, 7a, b.

1836. Lima? suspovauis, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp- 359, 342, pl. xvii, fig. 21.

1839. — aspera, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 1, p. 28 (partim).
? 1847. — _ susBovauts, A. d’Archiac. Mém. Soe. géol. de France, ser. 2, vol. ii,
p- 309.

_ — ornata, A. d’Orbigny. Pal. France. Terr. Crét., vol. iii, p. 551,
pl. eecexxi, figs. 6—10.
18505 —— — — Prodr. de Pal., vol. ii, p. 167.
— — — H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in
Deutschland, p. 192.

1867. — — E. Guéranger. Album Paléont. de la Sarthe, p. 19,
pl. xxiv, figs. 7, 12.
1869. — _ supovauis, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
: Croix (Matér. Pal. Suisse, ser. 5),
p- 168.
1870. — _ ornata, Pictet and Campiche. Ibid., pp. 169, 173.

1871. Rapuna (Acesta) ornata, F. Stoliczka. Paleont. Indica, Cret. Fauna S.
India, vol. in, p. 414.
1872. Lrwa ornata, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleontogra-
phica, vol. xx, pt. 1), p. 205, pl. xlii,
figs. 16, 17.

21877. — — A. Peron. Bull. Soc. géol. de France, ser. 3, vol. v, p. 502.
1877. — Ravturrana, A. J. Jukes-Browne. Quart. Journ. Geol. Soe., vol.
xxxili, p. 502, pl. xxi, fig. 2.
1893. — ornata, R. Michael. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlv,
p- 234.
Non 1852. — — A. Buvignier. Statist. géol., ete., de la Meuse, Atlas, p. 23,

pl. xviii, figs. 17—19.

Description—Shell compressed, ovate or subtrigonal, oblique, considerably
higher than long, with the ventral and posterior margins rounded. Apical angle
about 74°. Umbones small, close together. Anterior area rather small, depressed,
limited by a ridge, ornamented with ribs separated by broader grooves.

Ornamentation consists of numerous (65 to 70) fairly strong, rounded ribs of

6 CRETACEOUS LAMELLIBRANCHIA.

nearly equal size, but sometimes (chiefly near the posterior border) with smaller
intercalated ribs. The ribs diverge slightly from a nearly median line, and bear
short spiny or scaly projections at regular intervals but not usually with a con-
centric arrangement. The spines are rather nearer the inner than the outer side
of each rib. The grooves are narrow near the umbo but become broader in passing
ventrally, and at the ventral margin may exceed the ribs in breadth. The grooves
are rounded and (in some specimens) show transverse ridges. More or less distinct
erowth-lines occur at intervals.

Measurements :

(1) (2) (3) (4) (5) (6)
Length: «.°25; . 2052 220 20 Sliven eet eee enn
Height . 34 oot, AY 5 SRY 4 BB} 4 XD)

(1,3) Cambridge Greensand.

(2) Base of Chalk Marl, Folkestone.
(4,5) Upper Greensand, Warminster.
(63s y Haldon.

Affinities.—This species belongs to the same group as the Senonian forms L,
Dunkeri, Hagenow,' and L. muricata, Goldfuss.” It is distinguished from the
former by its smaller apical angle and by the spines on the ribs being placed more
closely together. L. muricata differs from LD. subovalis in haying fewer ribs with
their ornamentation developed into long scale-like projections, and in haying
oblique grooves in the interspaces.

Remarks.—A comparison of the type of Lima subovalis with examples of L.
ornata leaves no doubt as to their identity. ‘The type-specimen of the former is
somewhat worn, but sufficiently well-preserved for identification, and another
specimen on the same tablet shows the ornamentation quite clearly ; the shell is not
silicified, so that it was evidently not obtained from Blackdown—the locality given
by Fitton—but it has all the appearance of specimens found at Warminster.

The examples from the Cambridge Greensand were referred to L. Rauliniana,
VOrbigny,’ by Mr. Jukes-Browne. The interior of these is filled with phosphate,
and the shell, although in some respects well-preserved, is rather abraded, so that
the remains of the spines usually appear as notches on the inner side (that facing
the median line) of each rib. ‘The transverse ornamentation in the grooves is often
very distinct. Mr. Jukes-Browne has recently re-ex4mined these specimens and
agrees with me in thinking that they cannot be separated from JL. subovalis. I

1 «Neues Jahrb. fiir Min., etc.’ (1842), p. 556; Vogel, ‘Holliind. Kreide’ (1895), p. 17, pl. i, fig. 9;
Ravn, ‘ Mollusk. Danmarks Kridtaflej.’ (1902), p. 100, pl. i, fig. 14.

2 «Petref. Germ.,’ vol. 1 (1836), p. 89, pl. ciii, fig. 4; Vogel, op. cit., p. 17, pl. i, figs. 10, 11.

* «Pal. France. Terr. Crét.,’ vol. ii (1847), p. 542, pl. eecexvii, figs. 5—8; ‘ Prodr. de Pal.’ (1850),
vol. ii, p. 138; Pictet and Campiche, “ Foss. Terr. Crét. Ste. Croix” (‘ Matér. Pal. Suisse,’ ser. 5,
1869), p. 154, pl. elxvi, fig. 2.

LIMA. 7

have not been able to obtain specimens of L. Rauliniana, but it seems to differ from
L, subovalis in having a larger posterior ear and in other characters.

Types.—In the Bristol Museum (No. 1778), from the Upper Greensand, probably
of Warminster. The type of L. ornata is from the Cenomanian of Le Mans. The
specimen from the Cambridge Greensand figured by Jukes-Browne is in the
Sedgwick Museum, Cambridge.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Haldon.
Upper Greensand (zone of Pecten asper) of North Dorset, and Warminster. Cam-
bridge Greensand (derived). Rye Hill Sand of Maiden Bradley. Chloritic Marl
of Rocken End (Isle of Wight). Base of Chalk Marl (Greensand bed) of Folkestone.
Also recorded by the Geological Survey from the Cenomanian of Devon and Chard.

LIMA SCABRISSIMA, Sp. nov. Plate II, figs. 8a, b, 9a, b.

Description.—Shell compressed, ovate, height greater than length; antero-
dorsal margin rather short, straight or shghtly concave, ventral and posterior
margins forming a regular curve. Anterior area much depressed, sharply limited,
nearly smooth or with faint ribs. Apical angle about 92°. Posterior ear of
moderate size, with distinct growth-lines ; anterior ear small.

Ornamentation consists of a large number of narrow, rounded, more or less
undulating ribs separated by broader grooves. The ribs are generally of nearly
equal size, but smaller ones may be intercalated in the grooves. At regular
intervals the ribs bear scales or lappet-like projections which are arranged con-
centrically and may become vertical at their ends; these scales are continued
across the grooves as laminar projections. On the anterior and posterior ribs the
“scales”? become more pointed.

Measurements :
(1) (2) (3)
Length ; D4. ; 52 38 min.
Height ‘ 62 ; 58 : Ae

(1—3) Upper Greensand, Warminster.

Affinities —This species is near to Lima rhotomagensis, dOrbigny,' from the
Cenomanian of Rouen, but is distinguished from it by being much less convex, by
having a smaller anterior area and a smaller apical angle, and by the ribs being
relatively narrower and the grooves broader.

Types —In the Museum of Practical Geology.

Distribution Upper Greensand (zone of Pecten asper) of Warminster.

1 «Pal. Frane. Terr. Crét.,’ vol. iii (1847), p. 557, pl. eceexxil, figs. 8—11.

CRETACEOUS LAMELLIBRANCHIA.

Lima aspera (Mantell) 1822. Plate II, figs. 10, 11; Plate III, figs. la, b, 24.

1871.

1903.

Non 1836.

— 1839.

— 1841.

— 1846.

— 1847,

— 1850.

— 1900.

PuLaGrostoma ? aspERA, G. Mantell. Foss. 8. Downs, p. 129, pl. xxvi, fig. 18.
Lima aspera, J. Morris. Cat. Brit. Foss., ed. 2, p. 170.

— — F.J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix

(Matér. Pal. Suisse, ser. 5), p. 169.
Rapvuta (? AcestA) aspera, F. Stoliczka. Paleont. Indica, Cret. Fauna 8.
India, vol. iu, p. 415.
Lima aspera, A. J. Jukes-Browne. Cret. Rocks of Britain (Mem. Geol.
Survey), vol. iii, p. 450.

—_ — A. Goldfuss. Petref. Germ., vol. ii, p. 90, pl. civ, fig. 4.
— — H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 1, p. 23, pl. xxi, fig. 10.
— — F.A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p. 56.
— — A. H. Reuss. Die Verstein. der bohm. Kreideformat., pt. 2,
p. 34, pl. xxxviii, fig. 17.
— — A. dOrbigny. Pal. Franc. Terr. Crét., vol. iii, p. 566, pl.
eccexxy, figs. 3—6.
= — > Prod. der Pal., vol. ii, p. 248.
— — A. Alth. Beschreib. d. Umgebung von Lemberg (Haidinger’s
Naturwiss. Abhandl., vol. 11, pt. 2), p. 243.
— — A. v. Strombeck. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xv, p. 150. ;
= — . Favre. Moll. Foss. de la Craie de Lemberg, p. 135.
— — F.J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Maté. Pal. Suisse, ser. 5), pp. 171, 173.
— — A. Fritsch. Stud. im Gebiete der bohm. Kreideformat.: I,
Die Weissenberg. u. Malnitz. Schicht., p. 132,
fig. 118.
—_ —_ Tbid., III, Die Iserschicht., p. 114.
— — A. Peron. L’Hist. Terr. de Craie (Bull. Soc. Sci. hist. et
nat. de l’Yonne, ser. 3, vol. xii), p. 150.
— (Puactostoma) aspera, O. Griepenkerl. Senon. von Koénigslutter
(Paleont. Abhandl., vol. iv), p. 40.
— AspERA, G. Miiller. Mollusk. Untersen. v. Braunschweig u. Ilsede
(Abhandl. d. k. preussisch. geol. Landesanst.,
N.F., Heft 25), p. 26, pl. iv, fig. 5.
= — C. Gagel and F. Kaunhowen. Jahrb. a. k. preussisch. geol.
Landesanst. fiir 1899, p. 282.

Description —Shell ovate, higher than long, outline rounded, with the antero-
dorsal and postero-dorsal margins straightened ; convexity small. Umbones small,
pointed, close together, apical angle 80° to 90°. Anterior area deep, narrow.

LIMA. 9

Anterior ears triangular, rather small; posterior ears obtusely triangular, elongate,
with radial ribs.

Valves ornamented with numerous flattened ribs arranged on either side of a
line passing from the umbo to the ventral margin, from which they diverge slightly.
The ribs are nearly straight or slightly undulating, but are often bent abruptly
where they cross growth-lines. Surface of ribs nearly smooth, but sometimes
showing very fine concentric ridges or (when worn) oblique stria. On the inner
edge of each rib—that facing the middle lne—there are short, slit-like indentations,
above each of which a short spiny projection is seen in perfectly preserved
specimens. These slits and spines do not, as a rule, show a concentric arrange-
ment. The grooves separating the ribs are very narrow and are marked with
pits near the umbo and with transverse grooves ventrally. Sometimes near the
margins of the valyes new ribs are intercalated or old ones bifureate.

Measurements :

Onmeer Ga “@. oe) os
Mente eee sk | 80). 28 2 26 . O24 2: 19° . 16 mm.
Hemhiteeeeene oO 9.. 50 = sd. 85 . 26 . 28° . 21 |.
Numberot tibs®. 66 . 41 . 60 . 46 . 42 . 41 . 52
(1, 2, 3, 7) Totternhoe Stone, Burwell.
(4) » Cherry Hinton.

(5, 6) Chalk Marl, Folkestone.

Affinities—The Senonian form figured as Lima aspera by Goldfuss, Reuss, and
Fritsch is clearly distinguished from this species by the cheyron-like ornamentation
on the ribs. Pictet and Campiche suggest that Goldfuss’ species may be identical
with Lima Dunkeri, Hagenow,' from Riigen, but this view is not supported by the
figures given by Vogel and Rayn. The form figured by d’Orbigny has a larger
apical angle than L. aspera, Mantell, and does not show the spiny projections on
one side of the ribs.

The example figured by Reuss’ as Lima plana is similar in form to L. aspera,
Mantell, but does not appear to possess the spiny projections on the ribs.

T'ypes.—I have not been able to find the types.* They came from the Chalk
Marl of Hamsey and Stoneham.

Distribution.—Chiloritic Marl of Eastbourne. Chalk Marl of Folkestone, and
Blue Bell Hill (Burham). Totternhoe Stone of Arlesey, Burwell, Cherry Hinton,
and Stoke Ferry.

! «Neues Jahrb. fiir Min.,’ ete. (1842), p. 556.

2 «Verstein. béhmisch. Kreideformat.’ (1846), p. 35, pl. xxxviii, fig. 20.

8 The name aspera was used by Chemnitz (1784) for a recent species of Lima, but since that has
been shown to be a synonym of Lima scabra (Born, 1780) there does not appear to be sufficient reason
for giving a new name to the Chalk species which, for over eighty years, has been known as Lima

aspera, Mantell.

~

iD) CRETACEOUS LAMELLIBRANCHIA.

Sub-genus—Practostoma, J. Sowerby, 1814.
(‘ Min. Conch.,’ vol. i, p. 175.)

Lima (Pracrosroma) susriara, Rdmer, 1836. Plate III, figs. 5a, b,6—9. Text-
fies. 1, 2, 3.

1836. Lima supriarpa, F. A. Rimer. Verstein. nord-deutsch. Oolithen-geb., p. 79,
pl. xin, fig. 16.
— — puiana, Rimer. Thid., p. 80, pl. xiii, fig. 18.

1841. — _ supnrierpa, Rimer. Die Verstein. d. nord-deutsch. Kreidegeb., p. 57.

— — pLana, Rimer. ITbid., p. 57.

1877. — _ supriaipa, G. Bohm. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxix,
p. 235.

1896. — — A. Wollemann. Tbid., vol. xlviii, p. 836.

1900. — Wollemann. Die Biv. u. Gastrop. d. deutsch. u. holliind.

Neocoms (Abhandl. d. k. preussich. geol.
Land., N.F., pt. 31), p. 30.

Fig. 1—Lima (Plagiostoma) subrigida, Rémer. Claxby Ironstone, Lincolnshire. Right valve. Natural size.

Sedgwick Museum, Cambridge.
Description.—Shell convex, oval, height slightly greater than length; antero-
dorsal margin nearly straight, postero-dorsal much shorter and nearly straight, the

remainder rounded and forming a regular curve. Apical angle rather more than a

LIMA. 1]

right angle. Umbones of moderate size. Area large, with a large triangular
ligament pit near the middle but bending posteriorly. Anterior area large, deeply
depressed, especially near the ears. Lars rather large, the anterior triangular, the
posterior rather larger, more elongate ; surface with growth-lamelle only.

Surface ornamented with numerous (43 to 52) radial ribs, which are straight or
slightly undulatmg. The ribs are flattened; near the umbo they are separated by
narrow grooves, but in passing ventrally the grooves increase in width and become
as wide as or wider than the ribs. The grooves are rather shallow and rounded
The anterior and posterior ribs are narrower than the others. Near the umbo the
grooves are punctate, but in passing ventrally the pits soon become replaced by

e .
Fig. 2.—Lima (Plagiostoma) subrigida, Romer. Claxby Ironstone, Benniworth Haven. Right valve.
Natural size. Sedgwick Museum.

transverse furrows separated by ridges, and the latter may pass on to the ribs. On
the anterior area ribs are small or absent, but growth-lines are usually distinct.
Measurements :
(1) 2 @) @® 6 © @ & @®

Length . OOM Ome cms 72 040 65 5a. ol mm:
Height , Se ieee (so. 79 76 65 6b 36. 40 .,
Thickness. oo 63 S13) as
Number of ribs . 48 49 48 51 46 43 52 52 44

(1—9) Claxby Ironstone, Benniworth Haven.

Affinities —L. vigneulensis, Pictet and Campiche,'’ is distingwshed from
L. subrigida by its more quadrilateral outline, more numerous ribs and finer

1 «Terr. Crét. Ste. Croix’ (1869), p. 138, pl. elxii, figs. 5—8.

12 CRETACEOUS LAMELLIBRANCHIA.

grooves, and also by the earlier part of the shell beg nearly smooth. L. auber-
sonensis, Pictet and Campiche,' is relatively longer and has narrower grooves.
Remarks.—On account of the imperfect figures of L. subrigida given by Rémer,
the English specimens have not hitherto been referred to that species ; they agree
perfectly with the descriptions except in the number of ribs, but Dr. Wollemann
informs me that that character is variable. I have sent a specimen from the
Claxby Lronstone to Dr. Wollemann, and he is able to confirm my identification of
the species. Specimens from the Speeton Clay differ from those found im Lincoln-
shire in haying fewer ribs with relatively fewer grooves, but since this is a very
variable character it cannot be regarded as indicative of more than a local variety.

Bia. 3.—Lima (Plagiostoma) subrigida, Romer. Claxby Ironstone, Benniworth Haven, Area of right
valve, x §. Sedgwick Museum.

Types.—F rom the Hilsthon of Brunswick.
Distribution—Claxby Tronstone (zone of Belemnites lateralis) of Benniworth

Haven. Upper part of the Speeton Clay of Speeton.

Lima (PLAGiostoma), sp. ef. Orpignyana, Matheron, 1842. Plate III, figs. 10, a—e.

1842. Lrma Orpranyana, P. Matheron. Cat. Foss. des. Bouches-du-Rhone, p. 182,
pl. xxix, figs. 3, 4

1846. — — A. @Orbigny. Pal. Franc. Terr. Crcét., vol. iii, p. 530,
pl. cecexv, figs. 1—4.

1850. - —- @ Orbigny. Prodr. de Pal., vol. ii, p. 107.

1855. — - G. Cotteau. Moll. Foss. de Yonne, p. 100.

1865. — H. Coquand. Mon. Aptien de l’Espagne, p. 149.

1866. - P. de Loriol. Foss. Oolith. Corall. Valang. et Urgon.
Mt. Saltve, p. 82, pl. D, fig. 13.

1867. — aa de Loriol, in Favre. Rech. géol. Sans Savoie, vol. i,

p- 387, pl. C, fig. 24.
1869. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse, ser. 5),
p- 126, pl. clxi, fig. 4.
1871. Raputa (Acesta) Orpranyana, F’, Stolicaka. Palewont. Indica, Cret. Fauna
8. India, vol. iii, p. 414.

1 Loe. cit., p. 140, pl. clxiv, figs. 1, 2.

LIMA. 13

Description.—Shell moderately convex, oval, higher than long, ventral and
posterior margin rounded. Umbones sharp. Apical angle about 83°. Anterior
area depressed, limited by a rounded edge, ornamented with ribs. Kars with
distinct growth-ridges. Posterior ear higher than long, and larger than the
anterior ear.

Ornamentation consists of about 52 flattened ribs, slightly undulating,
separated by very narrow grooves with pits. Near the ventral margin the ribs
become divided by a median groove. Near the anterior and posterior margins
the ribs are rather narrower than elsewhere. A few moderately distinct growth-
lines occur.

Measurements :

Length . : : ; 20 mm.
Height , : ; ; USS Fe

Afjinities.—This is distinguished from L. villersensis (see below) by its more
numerous and narrower ribs.

Remark.—I have seen one specimen only, which is preserved in the British
Museum, No. L 15754.

Distribution.—Lower Greensand (Ferruginous Sands) of Shanklin.

Lima (PLaGiosroMa) VILLERSENSIS ? Pictet and Campiche, 1869. Plate LI, figs. lla,
11b, 12a, 6, 13.
? 1869. Lima vituersensis, I’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5),
pp. 127, 162, pl. clxi, fig. 5.
Description—Shell moderately convex, oval, higher than long, ventral and
posterior margins rounded. Umbones sharp. Apical angle about 85°. Anterior
area depressed, bounded by a sharp edge. Posterior ear larger than the anterior,
higher than long, with the outer angle obtuse, and with a few radial ribs.
Ornamentation consists of from 32 to 36 broad, flattened, nearly straight ribs,
separated by linear grooves with distinct pits. Near the anterior, and sometimes
near the posterior border, the ribs become narrower. <A few well-marked growth-
ridges may occur at distant intervals. Near the ventral margin of the valves
(ventral to a growth-ridge) the position of the ribs is sometimes slightly shifted,
and the number of ribs may increase owing to the fission of some.

Measurements :

(1) (2) (3) (4)
Length . 20 : 19 : 18 . 14 mm.
Height . 26:5). 25 A 22 : Dae;

(1—4) Lower Greensand, Faringdon.

14. CRETACEOUS LAMELLIBRANCHIA.

Affinities —1 have seen only a few examples of this form. They agree with
L. villersensis except in having a rather smaller apical angle. In this respect they
resemble L. Orbignyana, Matheron (see above), but they differ from that species in
possessing fewer and straighter ribs. I have not seen any undoubted example of
L. villersensis and am unable to state whether the apical angle is constantly larger
than in the English specimens. Pictet and Campiche say that it is about 95°, but
the specimen they figure possesses an apical angle of 90° only. In the English
specimens it is about 85°.

This is the form which was referred by Sharpe’ to L. consobrina, @Orbigny,
but it possesses considerably fewer ribs than that species.

Type.—L. villersensis is found in the Valanginian of Ste. Croix.

Distribution.—Lower Greensand of Faringdon.

os. 14, 15, 16a, b.

Lima (PLaciosroma) semiornata, d@’Orbigny, 1847. Plate ITI, figs.
Plate IV, fig. 1.

1847. Lrma semrornara, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ili, p. 555,
pl. cecexxii, figs. 1—3.

1850. — — @ Orbigny. Prodr. de Pal., vol. ii, p. 167.

1867. — — E. Guéranger. Album Paléont. de la Sarthe, p. 19,
pl. xxiv, fig. 13.

1870. — _— F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5),
p. 169.

1871. Rapvua (PLaciostomA) sem1oRNATA, F’. Stoliczka. Paleeont. Indica, Cret.
Fauna §. India, vol. iii, p. 414.
? 1885. _ — — F. Nétling. Die Fauna d. baltisch.
Cenoman. (Paleont. Abhandl.,

vol. ii), p. 15, pl. ii, fig. 4.

Description—Shell_ compressed, rounded, height and length nearly equal.
Antero-dorsal border straight or slightly concave. Umbones close together.
Anterior area depressed, with a sharp edge. Apical angle 120°.

Surface nearly smooth, shiny, with numerous, very fine, regular, concentric
linear ridges, and with radial punctate grooves near the umbo and near the
anterior and posterior margins. The grooves near the anterior margin are fewer
and more widely separated than those near the posterior margin.

1 «Quart. Journ, Geol. Soc.,’ vol. x (1853), p. 193 (sub-consobrina, VOrbigny, ‘Prodr. de Paléont.,’
(1850), p. 167).

LIMA. 15

Measurements :

(1) (2) (3) (4) (5)
Length . 32 : 31 ; 29 ; 29 ; 23 mm.
Height . 33 : 32 29 ; 26 Oe 2
(1, 2) Upper Greensand, Potterne.
(S30) .; 2 Ventnor.
G@) £ Blackdown.

Affinities.—This species is distinguished by its compressed valves and rounded
outline.

Type.—From the Cenomanian of Le Mans.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Potterne
(Devizes) and Blackdown. Upper Greensand (zone of Pecten asper) of Ventnor.
Chalk Marl of Folkestone.

Lima (Piaciostoma) Mnyert, sp. nov. Plate IV, figs. 2,3. Text-fie. 4.

-

1896. Lima srmpiex, A. J. Jukes-Browne. Quart. Journ. Geol. Soe., vol. lii, p. 152.

Description.—Shell ovate or subtrigonal, much compressed, a little higher than
5 > rn)
long, oblique, considerably inequilateral; antero-dorsal margin long and

Fie. 4.—Lima (Plagiostoma) Meyeri, sp. nov. Upper Greensand, Warminster. Museum of Practical Geology,
No. 8838. Left valve and antero-dorsal view. Natural size.

straightened, ventral and postero-ventral margins rounded. Umbones small, close
together. Apical angle from 90° to 100°. Anterior area depressed, long and
narrow, with a few radial ribs and vertical grooves. Posterior ear small; anterior
ear not seen.

Ornamentation consists of narrow, linear, shallow, pitted grooves which may

16 CRETACEOUS LAMELLIBRANCHIA.

be confined to the anterior and posterior parts of the valves or may extend over
the whole surface. The grooves are somewhat irregular and the interspaces are
broad and flattened. At distant intervals a few well-marked growth-rings occur,
beyond which, in some cases, the ribs cease.

Measurements :

(1) (2) (3) (4) (5)
Length . 69 ‘ 53 ; 48 : 42 . 34mm.
Height . 71 ‘ 56 : 52 , A toy Looe des

(1—5) Upper Greensand, Warminster.

Affinities.—This species differs from Lima seniornata (p. 14) m being larger,
relatively higher, more trigonal in outline, and in having the radial grooves more
extensively developed. It is distinguished from Lima simplex, @Orbigny,’ in
being much less convex, in the height being relatively less, the antero-dorsal
margin shorter, the anterior area smaller, and the anterior grooves less prominent.

The shell is relatively longer and the apical angle larger than in I. sub-conso-
brina, VOrbigny.’ It is also relatively longer, with a longer antero-dorsal margin
and the radial grooves less well developed, than in L. cretacea (p. 22).

T'ypes.—From Warminster. In the Museum of Practical Geology.

Distribution—Upper Greensand (zone of Pecten asper) of Warminster. Rye
Hill Sands and Chloritie Marl of Maiden Bradley. Cenomanian (Meyer's Beds 10
and 11) of Hooken and Dunscombe (Devon coast).

Lima (Praciosroma) GLoBposa (Sowerby), 1836. Plate LV, figs. 4 a—e, 5 a,b, 6 a—e.

1836. Lucrna? aruoposa, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
p. 335, pl. xi, fig. 2 (non Lucina
globosa, Romer, 1839).

1854. Lima euoposa. J. Morris. Cat. Brit. Foss., ed. 2, p. 171.

1895. —= — BE. Tiessen. “eitschr. der deutsch. geol. Gesellsch., vol.

xlvii, p. 473.

Description.—Shell very convex, of moderate size, oval, length considerably
ereater than height, outline rounded with the antero-dorsal margin long and
straightened. Umbones incurved, blunt. Apical angle about 118°. Anterior
area large, very deep, limited by a sharp edge, with radial ribs. Kars small.

Surface of valves polished, with faintly-marked growth-lines at mtervals ;

1 «Pal. Frane. Terr. Crét.,’ vol. iii (1847), p. 545, pl. cecexviii, figs. 5—7.

* Thid., p. 556, pl. cecexxii, figs. 4—7; L. sub-consobrina, d’Orbigny, ‘ Prodr. de Paléont.,’ vol. ii

(1850), p. 167.

LIMA. 7

ornamented with numerous pits having a regular radial and concentric arrange-
ment and giving rise (in some cases) to the appearance of slightly-raised radial
and concentric ribs. Near the ventral margin the pits become more elongated
(parallel with the margin) and their concentric arrangement may become wavy or
irregular. At the anterior and posterior margins the radial arrangement is often
more distinct than elsewhere. Sometimes on the median part of the valve the
concentric arrangement alone can be recognised.
Measurements :

(1) (2) (3) (4) (5) (6) (7) (8)
ibeneth = ol. 27 6. 25. Ok. 22 AU: ae LOe 2 mm:
Height . 25 . 23 21 21 19 van hGhe gee

33

(1—3, 5, 7, 8) Totternhoe Stone, Burwell.
(4) Chalk Marl, Ventnor.
(6); , Clevancy.

Affinities.—This species closely resembles Lima albensis, @ Orbigny,' from the
Gault of Ervy (Aube), Machéroménil (Ardennes), the Perte-du-Rhéne, ete. I have
not seen any specimens of LJ, albensis, but it appears to differ from L. globosa in the
absence of the punctate ornamentation and in having a smaller apical angle.

L. globosa is distinguished from L. Hoperi (see below) by its smaller size, more
inflated valves, and by the close-set rows of radial and concentric pits.

Type.—In the Museum of the Geological Society, No. 1538, from the Chloritic
Marl of the Isle of Wight.

Distribution —Gault of Folkestone. Red Limestone of Hunstanton. Upper
Greensand of Warminster. Cambridge Greensand (base of Chalk Marl). Chalk
Marl of Ventnor, Clevancy, Chilcomb well (Winchester), Burham, Folkestone and
Cherry Hinton. Cenomanian of Wilmington. Totternhoe Stone of Burwell.
Zone of H. subglobosus of Chilecomb and Fulbourn.

Lima (Pracrostoma) Horrri, Mantell, 1822. Plate IV, figs. 7, 8a, b
lla, b, 12a, b.

Da, b, 10,

>

1822. Pxracrosroma Horrri, G. Mantell. Foss. S. Downs, p. 204, pl. xxvi,
figs. 2, 3, 15.
— — — J. de C. Sowerby. Min. Conch., vol. iv, p. 111,

pl. eeelxxx.

1 «Pal. Franc. Terr. Crét.,’ vol. iii (1847), p. 541, pl. cecexvi, figs. 15, 16; ‘Prodr. de Paléo nt.,’
vol. ii (1850), p. 138; Pictet and Roux, ‘ Moll. Foss. Gris verts de Gentve ’ (1852), p. 488, pl. x1,
fiz. 9; Pictet and Campiche, ‘“ Foss. Terr. Crét. Ste. Croix” (‘Matér. Pal. Suisse,’ ser. 5, 1869),
p. 160.

3]
Vv

1869.

CRETACEOUS LAMELLIBRANCHIA.

Praciostoma Manrexui, A. Brongniart. Descript. géol. envir. de Paris.
In Cuvier’s Ossem. Foss., vol. ii,
pt. 2, p. 600, pl. iv, fig. 3.
Pacuytos Hoperi, M. J. L. Defrance. Dict. Sci. nat., vol. xxxvii, p. 207.
Pxiacrostoma puncratum, 8. Nilsson. Petrif. Suecana, p. 24, pl. ix, fig. 1.
Lima Horert, G. P. Deshayes. In J. G. Bruguicre, Hist. nat. des Vers et
des Moll. (Encye. méthod.), vol. ii, p. 349.
— Manverin, A. Goldfuss. Petref. Germ., vol. ii, p. 92, pl. civ, fig. 9.
— Horert, Goldfuss. Ibid., p. 91, pl. civ, fig. 8.
— — Lamarck. Anim. sans Vert. (ed. 2 by Deshayes and Milne-
Edwards), vol. vii, p. 120.
PuaAcrostoma punctatum, W. Hisinger. Lethzea Suecica, p. 54 (not pl. xv,
fig. 3).
Lima Hopert, H. G. Bronn. Letheea Geognost., vol. ii, p. 682, pl. xxxii, fig. 8.
— — H. B. Geinitz. Char. d. Schicht. u. Petref. des sachs.
Kreidegeb., pt. 1, p. 24 (? partim).
— Manreuui, Ff. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p. 58.
— Hopert, Rémer. Ibid., p. 58.
— Nrtssoni, Rimer. Tbid., p. 57.
— Gouprussi, Ff. v. Hagenow. Neues Jahrb. fiir Min., ete., p. 555.
— Manrexu, H. B. Geinitz. Grundr. d. Verstein., p. 472, pl. xx, fig. 13.
— Hopert, Geinitz. Ibid., p. 473, pl. xx, fig. 14.
= — A. H. Reuss. Die Verstein. der béhm. Kreideformat., pt. 2,
p. 34, pl. xxxviii, figs. 11, 12.
— Sowersyt, J. Miller. Petref. der Aachen. Kreidef., pt. 2, p. 67.
— Hoprri, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in
Deutschland, p. 192.
SoweERbyI, Geinitz. Ibid., p. 192.
— Hoprrt, A. Alth. Geogn.-paleont. Beschreib. von Lemberg (Haidin-
ger’s Naturwiss. Abhandl., vol. iii, pt. 2), p. 240.
— Manrenir, Rk. Kner. Verstein. v. Lemberg (Haidinger’s Natur-
wissensch. Abhandl., vol. ii, pt. 2), p. 29.
Puiaaiostoma Hopert, var., J. de C. Sowerby, in F. Dizon. Geol. Sussex,
pp. 348, 356 (p. 383, ed. 2),
pl. xxviii, fig. 21.
Lima Sowersyt, H. G. Bronn. Lethea Geogn., ed. 3, vol. ii, pt. 5, p. 278,
pl. xxxii, fig. 8.
— Horert, R. Kner. Denkschr. d. k. Akad. d. Wissensch. Wien, Math.-
nat. Cl., vol. iii, p. 318.
— -— J. Morris. Cat. Brit. Foss., ed. 2, p. 171 (partim).
— — S. Placketko. Das Becken von Lemberg (Jahresber. d. k. k.
zweit. Ober-gymnas. in Lemberg, 1863), p. 19.
- — A. von Strombeck. Zeitschr. d. deutsch. geol. Gesellsch.,
. vol. xv, p. 148.
a — KR. Drescher, Thid., p. 355.
- E. Favre. Moll. Foss. de la Craie de Lemberg, p. 137,
pl. xii, fig. 19.

1877.

1893.

1894.

LIMA. 19

Lima Horpent, F. Riimer. Geol. von Oberschles., p. 315, pl. xxxiv, fig. 10.

— F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matér Pal. Suisse, ser. 5),
pp- 171, 173.
Sowersyt, Pictet and Campiche. Tbid., p. 178.
-- H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palxonto-
graphica, vol. xx, pt. 2), p. 41, pl. ix,
figs. 13, 14.
— A. Fritsch. Stud. im Gebiete der béhm. Kreideformat. :
II, Weissenberg. u. Malnitz. Schicht.,
p- 133, fig. 120.
Horrrt, H. Schrider. Zeitschr. der deutsch. geol. Gesellsch., vol.
XXXxiv, p. 263.
Sowersyt, A. Fritsch. Stud. im Gebiete der béhm. Kreideformat. :
IIT, Iserschicht., p. 115, fig. 87.
Hopenrt, A. Peron. L’Hist. Terr. de Craie, p. 149.
(Praqaiostoma) Hoprerr. 0. Griepenkerl. Senon. vy. Kénigslutter
(Palezont. Abhandl., vol. iv),
p- 40.
Hopert, A. Fritsch. Stud. im Gebiete der bohm. Kreideformat. :
IV, Teplitz. Schicht., p. 84, fig. 78.
_ E.. Holzapfel. Die Mollusk. Aachen. Kreide (Paleontogra-
phica, vol. xxxv), p. 240, pl. xxvii, fig. 5.
(Puactostoma) Horert, HE. Stolley. Die Kreide Schleswig-Holsteins
(Mittheil. a. d. Mineralog. Instit.
Univ. Kiel, vol. i), p. 237.
Hopert, A. Fritsch. Stud. im Gebiete der bohm. Kreideformat.: V,
Priesener Schicht., p. 100.
— B. Lundgren. Mollusk. i Mammillatus- och Mueronata-
zonerna (K. Svenska Vet. Akad. Handl.
N. F., vol. xxvi, No. 6), p. 42.
- R. Leonhard. Kreideformat. in Oberschles. (Paleonto-
graphica, vol. xliv), p. 46.
— A. Hennig. Revis. Lamellibr. i Nilsson’s ‘ Petrifie. Suecana,’
(K. Fysiogr. Sillsk. i Lund. Handl., N. F.,
vol. viii), p. 30, pl. u, fig. 13.
(Piaciostoma) Horeri, H. Woods. Quart. Journ. Geol. Soc., vol. liii,
p. 383.
Horert, G. Miller. Mollusk. Untersen. v. Braunschweig u. Ilsede,
p. 24, pl. iv, fig. 12.
~- A. Wollemann. Jahrb. d. k. preussisch. geol. Landesanst.
fiir 1900, vol. xxi, p. 15.
= A. Wollemann. Liineburg. Kreide (Abhandl. d. k. preussisch.
geol. Landesanst., N. F., Heft 37), p. 58.
— J.P. J. Ravn. Mollusk. Danmarks Kridtaflej. : I, Lamellibr.
(K. Danske Vid. Selsk. Skrift. 6 Rekke,
nat. og math. Afd., vol. xi), p. 99, pl. ii
fig. 18.

20) CRETACEOUS LAMELLIBRANCHIA.

Non 1847. — — A. @ Orbigny. Pal. Frane. Terr. Crét., vol. iii, p. 564, pl.
eecexxiv, figs. L1O—-13.
— 1847. — Manreui, d’Orbigny. Tbid., p. 568, pl. eccexxvi, figs. 3—5.
— 1850. — Hoprert, d’Orbigny. Prodr. de Pal., vol. ii, p. 248.
— — — Manrettzt, d’Orbigny. Ibid., p. 248.
— 1877. — Horert, A. Fritsch. Stud. im Gebiete der bihm. Kreideformat. :
II, Weissenberg. u. Malnitz. Schicht., p. 134,
fig. 121.
— — Manrewut, Fritsch. Ibid., p. 134, fig. 122.
— 1872. — Hoprrt, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palaonto-
graphica, vol. xx, pt. 2), p. 40, pl. ix,
figs. 11, 12.
— 1881 — _ J. Kiesow. Cenomanverstein. a. d. Diluvium d. Umgeg.

Danzig’s (Schrift d. naturf. Gesellsch. in
Danzig, N. F., vol. v), p. 414, figs. 9, 10.
? — 1893. — sp.,cf. Hoprri, R. Michael. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xlv, p. 234.

Description—Shell convex, oval, rounded, considerably inequilateral, longer
than high. Antero-dorsal margin rather long, slightly convex or nearly straight ;
postero-dorsal margin rather short; the remainder forming a regular curve.
Umbones close together. Apical angle 115° to 117°. Kars rather small, with
erowth-lines; the posterior longer than high and larger than the anterior ear.
Anterior area large, deep, with a more or less sharp border, often with radial
grooves which vary in number and are more distinct near the umbo than
anteriorly.

Surface of shell nearly smooth. In the region of the umbo numerous linear
grooves with pits occur; these may also extend on to the anterior and posterior
parts of the shell, and in some cases they are present on the middle of shell,
reaching a part of the way or even quite to the ventral margin. The grooves are
slightly wavy, sometimes discontinuous, and are deeper near the anterior and
posterior margins, and often more widely separated near the former. New
erooves are introduced at various distances from the umbo.

Measurements :

Qg @2@ @ @® 6 ® @ (8) @ G0) @) G2)
Length 57 57 56 52 51 51 47 41 #37 34 31 31mm.
Height 52 50 52 50 47 46 42 39 32 32 28 26 ,,
(1) M. cor-anguinum zone, Gravesend. (5, 10) M. cor-anguinum zone, Northfleet.
(2) Uintaerinus band, Devizes Road, (8) Chalk Rock, Underwood Hall, Dulling-
Salisbury. | ham.
(3, 6, 12) A. quadratus zone, East Harnham. |
(4, 7) M. cor-anguinum zone, Gravesend.

(9, 11) B. mucronata zone, Norwich.

Affinities—This species was described by Brongniart under the name Plagios-
toma Mantelli from specimens which were sent to him by Mantell from near

LIMA. 21

Brighton—probably from Lewes. Mantell'’ regarded Plagiostoma Maitelli as a
synonym of his Plagiostoma Hoperi, and I think there can be no doubt as to the
correctness of that view.

Geimitz (1872) considered Lima Hoperi of Sowerby to be distinct from L. Hoperi
of Mantell, thinking that the former (which he named L. Sowerby?) was distinguished
by being almost smooth, whereas the latter is covered with radial grooves. The
smooth and the grooved forms agree exactly in shape, and between these extremes
in ornamentation every gradation may be seen. Moreover, although one of the
specimens figured by Mantell (fig. 3) is ornamented all over, the others (figs. 2, 15)
possess grooves on the sides only. I think, therefore, that there can be no doubt as
to the identity of L. Hoperi of Sowerby and FL. Hoperi of Mantell. Further, it
should be noted that Sowerby’s specimens were sent to him by Mantell as examples
of his L. Hoperi.

The specimens figured by Geinitz (1872) as 1. Hoperi (from the Pliner-kalk of
Strehlen) are relatively higher (especially fig. 11) than Mantell’s species, and are
probably examples of L. cretacea (see below).

I. Hoperi of @Orbigny® differs in having a smaller apical angle, in being
relatively higher, much compressed, and with the grooves more widely separated.
It may, however, be only a variety of . Hoperi, Mantell. I have seen undoubted
examples of L. Hoperi, Mantell, from the Senonian of Marromme (near Rouen),
Lillebonne (Seine-Inférieure), and from other French localities. The form de-
seribed and figured by d’Orbigny as L. Mantelli is referred to below (p. 23).

LL. Lamberti of Peron,* from the zone of Micraster breviporus of Joigny, may be
only a variety of L. Hopert. It is stated to differ chiefly in its greater length, but
in this respect it can, I think, be matched by some undoubted varieties of L.
Hopevi.

For the relation of L. Hoperi to L. globosa see page 17, and to L. eretacea
see page 25.

Remarks.—This species varies considerably in the extent of the ornamentation.
Some examples are smooth, save for the pitted grooves near the umbo; in many
cases the grooves are continued on to the sides of the shell; less frequently they
extend to the middle of the valve, and may even reach the ventral margin. I
have not seen sufficient examples, of which the exact horizons are known, to enable
me to determine whether any of the varieties are characteristic of certain zones.

T'ypes.—I have not seen the types. The specimens figured by Sowerby are in
the British Museum. The types, and also Sowerby’s specimens, came from the
Upper Chalk (probably from the zone of Micraster cor-testudinarium or the zone of

1 «Trans. Geol. Soc.,’ ser. 2, vol. iii (1835), p. 206.
2 See Jukes-Browne, ‘ Quart. Journ. Geol. Soe.,’ vol. lii (1896), p. 152.
3 * Hist. Terr. de Craie’ (1888), p. 151, pl. ii, fig. 1.

22 CRETACEOUS LAMELLIBRANCHIA.

M. cor-anguinum) near Lewes. An example from Cambrai is in the d’Orbigny
Collection at Paris, but it is probably not the specimen figured in the ‘ Paléontologie
Francaise.’

Distribution —(i) Zone of Terebratulina of Beyendean, near Brighton."

(ii) Zone of Holaster planus of Winchester, Lewes, Dover, Kenley, Cuxton.
Chalk Rock of Boxmoor, Luton, Underwood Hall (Dullingham), Westley
Waterless.

(iii) Zone of Micraster cor-testudinarium of Lewes, Dover, Purley, Strood,
Chatham, Swaffham * (Norfolk).

(iv) Zone of Micraster cor-angquinum of Winchester, Porton, Witherington,
Quidhampton, Lewes, the Sussex coast, St. Margaret’s, Gravesend, Northfleet,
Halling Pit (South Croydon).

(v) Zone of Marsupites testudinarius of the coasts of Sussex, Thanet, and
Yorkshire. Uintacrinus band of Devizes Road, Salisbury.

(vi) Zone of Actinocamax quadratus of Kast Harnham, Hursley (Winchester),
the coasts of Sussex and Yorkshire.

(vii) Zone of Belemnitella mucronata of the Dorset coast and Norwich,

(viii) Chalk of Trimingham.

Lima (PLaciostoma) cRETACEA, nom. noy. Plate IV, figs. 18, 14 a—e, 15. Plate V,
»
figs. la, b, 2, 3, 4a, b.

21847. Lima Manrenui, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 568,
pl. eecexxvi, figs. 83—5 (non L. Man-
telli, Brongniart).

?1850. — — — Prodr. de Pal., vol. ii, p. 248.

- — mviuscuna, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 347
(p. 382, ed. 2), pl. xxviii, fig. 14,
(non DL. leviuscula, Sowerby,

1822).
21872. — Hopent, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palzontogra-
phiea, vol. xx, pt. 2), p. 40, pl. ix, figs. 11,12.
21877. — _- A. Fritsch. Stud. im Gebiete der bdhm. Kreideformat. : IT,

Weissenberg. u. Malnitz. Schicht., p. 134,
fie. 121.

— — Manet, Fritsch. Ibid., p. 184, fig. 122.

? 1888. — — A, Peron. L’Hist. du Terr. de Craie, p. 151,

Description.—Shell of small convexity, oval, very inequilateral, higher than long.
Antero- and postero-dorsal margins nearly straight, the remainder forming a

! Also recorded from the Terebratulina zone of South Dorset by Dr. Barrois.
2 This may be from the M. cor-anguinum zone.

LIMA. 23

a

regular curve. Umbones small, close together. Apical angle usually about 100°,
but sometimes only 90°. Kars small, the posterior larger than the anterior.
Anterior area of moderate size, very deep, with a sharp edge and numerous radial
ribs.

Ornamentation consists of numerous, well-defined, radial grooves with distinct
pits, covering the entire surface of the shell. The grooves are straight or slightly
wavy, and in some cases are linear, in others broader, the latter giving the appear-
ance of flattened or rounded ribs to the interspaces. ‘The pits in the grooves some-
times extend into the sides of the ribs. New grooves may be introduced near the
ventral margin or occasionally near the middle of the valve. In well-preserved
specimens very fine concentric ridges are sometimes seen. A few growth-rings
are usually present.

Measurements :

CZ) IC) 1G) 6) Gr) 8) (8)
iteneth 382) 52 26 21 21 17 16 12 11mm.
Height; 37 30 30 24 22 19 19 14 12

bP)

(1) H. planus zone, Cuxton. (5—7) A quadratus zone, East Harnham.
(2) 5 » Cheveley. (8) M. cor-angquinum zone, Witherington.
(3) Ps » Borsted. (9) Uintacrinus band, Devizes Road, Salisbury.

(4) A. quadratus zone, Whaddon railway cutting, |

near Salisbury. |

Afjinities.—This species is distinguished from Lina Hoperi by having a smaller
apical angle, by being relatively higher and shorter, with the valves less convex,
the anterior area relatively smaller, the entire surface of the shell always orna-
mented, and the grooves usually deeper.

The specimen figured by d’Orbigny as Lima Mantelli is similar in form to some
examples of L. cretacea, but d’Orbigny states that the furrows are shallow and
without pits. A specimen, however, in the d’Orbigny Collection at Paris shows
pits in the grooves.

Tama leviuscula, Sowerby (in Dixon) is probably a small example of this
species, but its locality and horizon are not stated.

One of the specimens from the Pliner-kalk of Strehlen figured by Geinitz
(1872) as L. Hoperi (fig. 11) agrees very closely with this species.

Distribution.—Zone of Terebratulina of Winchester. Zone of Holaster planus of
Twyford and Cheveley. Zone of Micraster cor-testudinarium of Borstal and
Cuxton. Zone of M. cor-anguinum of Micheldever, Witherington and Camp Hill
(South Wiltshire). Zone of Marsupites of Highfield. Uintacrinus band of Devizes
Road (Salisbury). Zone of Actinocamaw quadratus of Winchester, Kast Harnham,
West Harnham, and Milford (Salisbury). Zone of Belemnitella mucronata of
Norwich. Chalk of Trimingham.

24, CRETACEOUS LAMELLIBRANCHIA.

Lima (PLaciosroma) Marnorrana, d’Orbigiy, 1847. Plate V, figs. 6a, b, 7a, b.

1847. Lima Marrorrana, A. dOrbigny. Pal. Franc. Terr. Crét., vol. iii, p. 561,
pl. eecexxiv, figs. 1—4.
1850. — — @’ Orbigny. Prodr. de Pal., vol. ii, p. 247.
1889. — (Raputa) Marroriana, O. Griepenkerl. Senon. von Koénigslutter
(Paleont. Abhandl., vol. iv), p. 39.

Non 1850. -- Marorriana, A. Alth. Geogn.-pal. Beschreib. v. Lemberg (Haidinger’s
Naturwiss. Abhandl., vol. iii, pt. 2), p. 240,
pl. xii, fig. 25. (L. Althi, Favre).

Description.—Shell of moderate convexity, oval, more or less trigonal. Antero-
dorsal margin rather long, nearly straight ; postero-dorsal margin much shorter ;
the remainder forming a regular curve. Umbones rather small, pomted. Apical
angle about 105°. Anterior area large, deeply depressed, sharply limited,
ornamented with 10 to 12 strong, rather narrow ribs, which bear, in places, small
nodular projections. Ears rather large, with growth-ridges, without ribs; the
posterior rather larger than the anterior ear.

Ornamentation consists of 30 to 32 broad ribs with a few smaller ribs near the
posterior margin; the ribs are smooth, with flattened or somewhat rounded
summits, and are separated by narrow rounded grooves. The grooves show, in
places, transverse ridges and grooves which may extend to the sides of the ribs,
giving them a notched appearance. Near the ventral margin, especially in old
specimens, the ribs become more flattened and the grooves shallower.

Measurements :

(1) (2)
Length et) ; 27 mm.
Height. ; : . 60 : 28

39

(1, 2) Upper Chalk (B. mucronata zone), Norwich. - The measurements of the larger specimen are
approximate only.

Affinities —This is distinguished from other species found in the Chalk by its
strong ribs. In Lima Althi, Favre, the ribs are more numerous and not so broad.

Lima Marrotiana differs from most of the species which are referred to
Plagiostoma im having much stronger ribs, but in other respects it agrees closely
with that sub-genus.

Remarks.—The only specimens I have seen are from Norwich, where it appears
to be rare. he shell is usually more or less crushed, so that its proper outline is
distorted.

%

LIMA. 95

Types.—D’Orbigny’s specimens came from the Lower Senonian of Dordogne,
Charente-Inférieure, Cambrai, and Aube.
Distribution.—Zone of Belemnitella mucronata of Norwich.

Sub-genus—Aczsta, H. and A, Adams, 1858.

(‘ Genera of Recent Mollusca,’ vol. ii, p. 558.)

Lima (Acesta) tonca, Rémer, 1841. Plate V, figs. 8a,b, 9—11, 12a, b.

1836. Lima ELonaata, Ff. A. Rimer. Die Verstein. d. nord-deutsch. Oolith.-geb.,

1841.
1847.

1850.

1865.

1868.

1869.

1871.

1877.

1883.

1884.

? 1895.
1896.

1900.

p. 79, pl. xiii, fig. 11 (non elongata,
Sowerby).
LonGa, Rimer. Die Verstein. d. nord-deutsch. Kreidegeb., p. 57.
— A. dOrbigny. Pal. Franc. Terr. Crét., vol. iii, p. 529, pl.
ceecexiy, figs. 13—16.
— — Prodr. de Pal., vol. ii, p. 81.
— 4H. Coquand. Mon. Aptien de l’Espagne, p. 149.
— P.deLoriol. Valangien d’Arzier. (Matér. Pal. Suisse, ser. 4),
p. 41, pl. iii, fig. 11.
— F.J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser. 5), p. 128,
pl. elxi, figs. 6, 7.
— W.A. Ooster. Protozoe Helvetica, vol. ii, pp. 104, 123.
— G. Bihm. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxix,
p- 235.
— W. Keeping. Foss., ete., Neoc. Upware and Brickhill, p. 112,
pl. v, fig. 6.
n. sp., O. Weerth. Die Fauna des Neocom. im Teutoburg. Walde
(Paleont. Abhandl., vol. ii), p. 51.
(Puaarostoma) ef. Roprnauprina, F. Vogel. Holliind. Kreide, p. 56.
tones, A. Wollemann. Zeitschr. der deutsch. geol. Gesellsch.,
vol. xlviii, p. 836.
= — Die Biv. u. Gastrop. d. deutsch. u. holland.
Neocoms (Abhandl. d. k. preussisch. geol.

Land., N. F., pt. 31), p. 27.

Description—Shell compressed, sub-triangular, rounded, considerably higher
than long, of small obliquity. Posterior and ventral margins convex; anterior
margin straight. Umbones pointed, close together. Apical angle small—about 70°.
Posterior ear large, not separated from the rest of the valve by a depression,
ornamented with radial ribs. Anterior ear smaller, much higher than long.

a

26 CRETACEOUS LAMELLIBRANCHIA.

Anterior area lanceolate, depressed, limited by a sharp edge, ornamented with
radial ribs.

Ornamentation consists of very numerous, small, somewhat flattened ribs,
separated by much narrower grooves. The ribs are usually wavy, and are not all
of equal size; posteriorly smaller ribs sometimes alternate with larger. The
grooves are punctate and vary somewhat in width. A few distinct growth-lines
are seen, below which the direction of the ribs may undergo some deflection.

Measurements :

Q) (2) (3) (4) (5) (6)

Length : . Bt 39 3 23 21 20 mm.
Height , eb2 58 56 37 35 Se lose

(1, 2, 3, 5) Lower Greensand, Upware.
(4) Tealby Limestone, North Willingham.
(6) Speeton Clay, Speeton.

Ajiinities—Lima longa has a smaller apical angle and is relatively shorter than
L. widata, Deshayes'; it is also clearly distinguished by the absence of the prominent
concentric scales, and by the occurrence of pits in the grooves.

Remaris.—In some cases, especially when the specimens are not perfectly
preserved, the ribs (as remarked by Wollemann) become indistinct on the middle
of the shell. This is the case in specimens from the Tealby Limestone, and in some
from the Speeton Clay, in which the middle part of the shell is almost smooth.
The outline of the shell and the relative size of the posterior ear are rather variable.

A specimen from West Dereham (Plate V, fig. 13) possesses finer ribs, but may
perhaps be only a variety of this species.

T'ypes.—From the Hilsthon of Eligser Brink. A specimen from the same
locality (imperfect on the posterior side of the umbo) is figured by @’Orbigny and
is preserved in the Museum of Paleontology at Paris. ‘Two of the specimens from
Upware figured by Keeping are in the Sedgwick Museum, Cambridge, and another
is in the collection of Mr. J. F. Walker.

Distvibution.—Lower Greensand of Upware, Potton, and Brickhill. Tealby
Limestone (zone of Belemnites brunsvicensis) of North Willingham. Upper part of
Speeton Series of Speeton.

Lima (Acrsta) chypretrormis, @’ Orbigny, 1847. Text-figure 5.

1847. Lima crypervormis, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ii, p. 546,
pl. cecexvii, figs. 9, 10.
1850. — — @Orbigny. Prodr. de Pal., vol. ii, p. 166.

' See d’Orbigny, p. 528, pl. cccexiv, figs. I—12; Pictet and Campiche, p. 133, pl. clxii, fig. 1.

|

27

LIMA.

1869. Lima cryperrormis, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse ser. 5),

p. 168.

Rapunta (Acesta) chyprrrormis, F. Stoliczka. Palont. Indica, Cret.
Fauna S. India, vol. iii,

p- 414.

1871.

Description.—Shell very large, compressed, oval, rounded, only slightly oblique.
Antero-dorsal margin more or less

Height equal to or slightly greater than length.

Fie. 5.—Lima (Acesta) clypeiformis, d’Orbigny. Upper Greensand, Chard. Right valve. Taunton
Museum, x 3.
Ears rather small, the anterior larger than the

straightened and relatively short.
Surface of shell smooth, except for growth-lamell at intervals.

posterior.
Measurements :
Length . : : : : : : 160 mm.
Height : ; ; ‘ ; : ee ilo ee
Upper Greensand, Chard.

28 CRETACEOUS LAMELLIBRANCHIA.

Affinities —Lima subelypeiformis, Futterer,' is stated to be related to L. elypet-
formis.

Remarks.—This is the largest species of Jima known in the Cretaceous of
England. I have seen two specimens only, one of which is in the Museum of the
Somersetshire Archeological and Natural History Society at Taunton, and the
other in the Exeter Museum. ‘The occurrence of this species in England was first
recorded by Mr. Jukes-Browne.’

T'ype.—D Orbigny’s specimens came from the Cenomanian of Le Mans, ete.

Distribution.—Topmost bed of the Upper Greensand of Chard.

Sub-genus—Mantetium, J. PF’. Bolten, 1798.
(‘ Mus. Bolten.,’ 2, p. 160.)
Liwa (MANTELLUM) PARALLELA (Sowerby) 1812. Plate V, figs. 14, 15 a—d.
1812. Moprona paraLLELA, J. de C. Sowerby. Min. Conch., vol. i, p. 31, pl. ix
(right-hand top figure).

1842. Tama rnecans, A. Leymerie. Mém. Soe. géol. de France, vol. v, p. 27,
pl. vi, fig. 6. (Non Dujardin, non Nilsson. )

1845. — snonaata, FZ. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 248.

1846. — exeaans, A. Leymerie. Statist. géol. et min. de l’Aube, pl. vi, fig. 7.

1847. — Corranprina, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. ii, p. 537,
pl. eecexvi, figs. 1—5.

1850) .— — @ Orbigny. Prodr. de Pal., vol. ii, p. 119.

1854. — vparauuea, J. Morris. Cat. Brit. Foss., ed. 2, p. 171.

1855. Corranprina, G. Cotteau. Moll. Foss. de l’Yonne, p. 101.

1858. — -- J. Vilanova-y-Piera. Mem. geog.-agric. de Castellon,

pl. ii, fig. 15.

— — parauuena, F. J. Pictet and E. Renevier. Foss. Terr. Aptien (Matér.
Pal. Suisse, ser. 1), p. 126,

Plo s

1865. — _ H. Coquand. Mon. Aptien de Espagne, p. 148.

1869. — Corraupina, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5),

p- 151, pl. elxvi, fig. 1.

1883. — rFarrinaponensts, W. Keeping. Foss., ete., Neoc. Upware and Brick-
hill, p. 112, pl. v, fig. 12.
1884. — Corranptna, O. Weerth. Die Fauna des Neocom. im Teutoburg.

Walde (Palexont. Abhandl., vol. ii), p. 52.

1 «Kreidebild. d. Santa Croce in den Venetianer Alpen’ (Palewont. Abhandl., vol. vi, 1892),
p. 78, fig. 28.
2 «Proc. Somerset Archeeol. and Nat. Hist. Soc.,’ vol. xlix, 1903.

LIMA.

29

1895. Lima Corranprna, G. Maas. Zeitschr. der deutsch. geol. Gesellsch., vo .

xlvii, p. 267.

— — (Ravvra) Corranprna, PF. Vogel. Holliindisch. Kreide., p. 56.

1900. — Corranpina, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.
hollind. Neocoms (Abhandl. d. k.
preussisch. geol. Land., N. F., pt.
31), p. 35, pl. ii, figs. 2, 3.

Non 1847. — _ parauueta, d’Orbigny. (See p. 31).

Description.—Shell moderately convex, oblique, oval or rounded-oblong, higher
than long. Antero-dorsal margin long, nearly straight, more or less parallel with the
postero-ventral margin; postero-dorsal margin short, more or less nearly straight.
Anterior margin regularly rounded. Umbones sharp, only slightly curved; apical
angle about 90°. Kars of moderate size. Anterior area rather large, slightly
conyex ventrally, depressed near the umbo, usually smooth except for growth-
lines.

Ornamentation consists of 18 to 20 principal ribs, and sometimes of a few
smaller ribs near the posterior margin. The principal ribs are roof-like with sharp
summits; they are strongest on the antero-dorsal part of the valve and become
less elevated and rather more widely separated in passing posteriorly ; the two or
three anterior ribs (near the anterior area) are rather smaller and closer together.
A small rib occurs at the bottom of the furrows between the main ribs; smaller
linear ribs may occur on the sides of the principal ribs, especially on the posterior
part of the shell. Fine concentric growth-lines are seen on the ribs and furrows.

Measurements :

Qa @ @ @® © © @ 6)
Length . 26 26 25 23 238 22 19 14mm.
Hee eohe 22° 20 19° 18 -17 16 41 -,,
(1, 4) Perna-bed, Atherfield.
(2, 5) Hythe Beds, Lympne.
(3) Lower Greensand, Upware.
(6, 7) Hythe Beds, Hythe.
(8) Ferruginous Sands, Shanklin.

Affinities —This species is closely allied to L. Royeriana, VOrbigny,' but in
the latter the ribs do not decrease in size nor become more widely separated on
the posterior part of the shell, and the small rib in the furrows is absent or
indistinct.

L. parallela is distinguished from L. gaultina (p. 31) by being relatively
shorter and less compressed, by the ribs on the posterior part of the shell being

1 «Pal. Franc. Terr. Crét.,’ vol. iii (1847), p. 527, pl. eecexiv, figs. 5—8; Pictet and Campiche,
‘Terr. Crét. Ste. Croix’ (1869), p. 142, pl. elxiv, figs. 4, 5.

30 CRETACEOUS LAMELLIBRANCHIA.

more distinctly smaller than those on the anterior part, and by the presence of
the small rib at the bottom of each groove. See also L. furringdonensis (below).

L. expansa, Forbes,’ from the Hythe Beds of Hythe, is known to me only from
the type specimen which is preserved in the Museum of the Geological Society
(No. 2056). It is an internal cast in clay, somewhat crushed, and shows the
ribbing only imperfectly. I think it is probably an example of L. parallela, but
more specimens from the same horizon are needed before a confident opmion can
be given. Similar remarks apply to L. lingua, Forbes,’ which comes from the same
horizon and locality, and is likewise preserved in the Museum of the Geological
Society (No. 2058).

This and the following eight species are provisionally referred to the sub-genus
Mantellum, with which they agree in the form of the shell and, in many cases, in
the general character of the ornamentation. hey differ, however, from the type
of Mantellum in haying the valves closed or almost closed, but there is, as Phillpi
has pointed out, every transition from the species in which the valves gape widely
to others in which they are closed.

Remarks.—This species shows a fair amount of variation in the proportions of
length and height, and also in the obliquity of the shell.

The type-specimen of L. parallela is an internal cast, and consequently all
writers have found it practically impossible to make out the characters of the
species from Sowerby’s figure. A comparison of the type with better preserved
specimens leaves no doubt in my mind that Sowerby’s species is really identical
with the form described by d’Orbigny as LF. Cottaldina. The latter author
referred a species found in the Gault (. gaultina, p. 31) to L. parallela, Sowerby.

Types. —The type is from the Hythe Beds of Maidstone and is preserved in the
British Museum (No, 43,292). The specimen from Upware figured as L. farring-
donensis by Keeping is in the Sedgwick Museum, Cambridge.

Distribution.—Perna-bed and Atherfield Clay of Atherfield. Ferruginous Sands
of Shanklin. Hythe Beds of Hythe, Lympne, and Maidstone. Sandgate Beds of
Sevenoaks. Folkestone Beds of Folkestone. Lower Greensand of Faringdon and
Upware. Speeton Clay of Speeton.

Lima (Manrenium) rarrtNaponensts, Sharpe, 1853.
1853. Lrma rarrinaponensis, D. Sharpe. Quart. Journ. Geol. Soc., vol. x, p. 198,
pl. vi, fig. 2.
Non 1883. — — W. Keeping. Foss., ete., Neoc. Upware and Brick-
hill, p. 112, pl. v, fig. 12.
1 «Quart. Journ. Geol. Soc.,’ vol. i (1845), p. 249, pl. iii, fig. 11.
2 Thid., p. 249, pl. iii, fig. 10.

LIMA. 3]

Remarks.—The chief character in which Lima farringdonensis differs from
L. parallela seems to be in the possession of well-marked ribs over the whole of
the anterior area. It also differs from the majority of examples of DL. parallela in
that the ribs only decrease in size to a very small extent in passing from the
anterior to the posterior part of the shell; and further, the shell is less inequilateral
than is usual in LZ. parallela.

I am inclined to regard Lima farringdonensis as not more than a variety of
L. parallela, but without better material it is impossible to express a confident
opinion. Almost all the specimens seen are in the condition of internal casts in a
brownish ferruginous sandstone.

The figure given by Sharpe is taken from a gutta-percha cast of an

Type.
external mould. It was obtained from Seende and is preserved in the Museum of
the Geological Society.

Distribution.—Lower Greensand of Seende and Faringdon.

Lima (MAN?TELLUM) GAULTINA, nom. noy. Plate V, figs. 16—20.

21827. Pxracrosroma ELoneata, J. de C. Sowerby. Min. Conch., vol. vi, p. 113,

pl. dlix, fig. 2 (upper figure only).

1847. Lima parauuena, A. d’Orbigny. Pal. Frane. Terr. Crét., vol. i, p. 539,
pl. eccexvi, figs. 11—14.

1850. — -- ad’ Orbigny. -Prody. de Pal., vol. ii, p. 138.

1855. — — G. Cotteau. Moll. Foss. de ?Yonne, p. 101.

1854. — xnoneara, J. Morris. Cat. Brit. Foss., ed. 2, p. 171 (partim).

1875. — — A. J. Jukes-Browne. Quart. Journ. Geol. Soc., vol. xxxi,

p- 296.

1897. — parautena, Rk. B. Newton. Proc. Dorset Nat. Hist. and Antiq. Field
Club, vol. xvii, p. 88, pl. ii, fig. 11.

1900. — — E. T. Newton and A. J. Jukes-Browne. Cret. Rocks of

Britain, vol. i, p. 449.

Non 1850. Puaciosroma parauuezus, J. de C. Sowerby in F. Dixon. Geol. Sussex,
p- 356 (p. 386, ed. 2), pl. xxviii,

fig. 16 (=L. elongata, Sowerby).

Description.—Shell rather compressed, sub-quadrangular or nearly oblong, very
oblique, much longer than high, rounded posteriorly ; antero-dorsal margin long
and nearly straight, almost parallel with the postero-ventral margin. Apical angle
about 100°. Umbones pointed, close together. Ears of moderate size, the anterior
larger than the posterior. Anterior area large, slightly concave dorsally, orna-
mented with fine radial ribs.

Ornamentation consists of 18 to 20 main ribs with a few smaller ribs pos-
teriorly. The ribs are strong, with sharp summits, but become somewhat

32 CRETACEOUS LAMELLIBRANCHIA.

weaker posteriorly. The sides of the ribs are ornamented with fine radial ribs, and
at the summit there is sometimes a rib with pointed projections. Concentric
growth-lines are present.
Measurements :
(1) (2) (3) (4) (5) (6)

Length . : 39 34 29 29 28 17 mm.
Heicht? , .. 28. 428° 90; A Mig aecomnemnioe

(1, 4) Gault, Black Ven.
(2, 8, 5, 6) Gault, Folkestone.

Affinities —Lima Iteriana, Pictet and Roux,’ appears to differ from this species
in having a small rib at the bottom of the groove, and in being relatively shorter.
Pictet and Campiche state that the small rib is not always present. I have seen
no trace of such a rib in even the best preserved examples of L. gaultina. See also
Lima elongata (p. 36).

Remarl:s——One of the specimens figured by Sowerby as Plagiostoma elongata
(the upper figure 2 of Plate DLIX) is probably an example of this species, but since
it is an internal cast only, it is difficult to be sure of its identity without seeing
other specimens from the same horizon. The specimen in question, however,
agrees in form and in the characters of the ribs with other internal casts which
undoubtedly belong to this species. D’Orbigny referred this species to Lima
parallela (Sowerby) and also included with it L. elongata, Sowerby (p. 34).

T'ypes.—The specimen figured by Sowerby, mentioned above, is stated to come
from the “ Greensand of Folkestone.” D’Orbigny’s specimens of Lima parallela,
VOrbigny non Sowerby, came from the Gault of Gérodot and Dienville (Aube).

Distribution —Gault of Folkestone (zones ii, vii, ix). Gault of Ventnor and
Black Ven. Cambridge Greensand (derived). Upper Greensand (zone of
Schlanbachia rostrata) of Devizes. Internal casts from the Speeton Clay (zone of
Belemnites jaculum, C 11) seem to be indistinguishable from this species.

Lowa (Manrentum) irertineata, Jukes-Browne, 1877. Plate VI, figs. la, b.

1877. Lima unrer“ineata, A. J. Jukes-Browne. Quart. Journ. Geol. Soc.,
vol. xxxiii, p. 502, pl. xxi, fig. 10.

Description.—Shell moderately convex, rounded-oblong. Umbones and ears
not seen.

1 Measured perpendicular to the hinge-line.

2 «Moll. Foss. Grés verts de Gentve’ (1852), p. 484, pl. xl, fig. 5; EF. J. Pictet and G. Campiche,
‘Poss. Terr. Crét. Ste. Croix’ (Mater. Pal. Suisse, ser. 5, 1869), p. 156, pl. clxvi, figs. 4, 5.

LIMA. 33

Ornamentation consists of 10 to 12 strong ribs with broad interspaces. On the
posterior part of the shell the ribs are more widely separated and the interspaces
flatter than on the anterior part. In the interspaces there are small radial ribs
separated by broad spaces.

Remarks.—The only specimens seen are a few imperfect internal moulds with
very small portions of the shell preserved. L. interlincata appears to be allied to
L. qaultina (see above) but is distinguished by possessing fewer ribs with broader
and flatter interspaces. The smaller radial ribs are perhaps also better developed
than in LZ. gaultina.

Type.—In the Sedgwick Museum, Cambridge.

Distribution —Cambridge Greensand (derived from the Gault).

Lima (Mayvetium) intermepia, d’Orbigny, 1847. Plate VI, figs. 2a,b, 3, 4a—e.

1847. Lima rnrermepia, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 550,
pl. cecexxi, figs. 1—5.

1850. — _- @’ Orbigny. Prodr. de Pal., vol. ii, p. 167.
1869. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5),
p. 168.
21877. — — A. Fritsch. Stud. im Gebiete der b6hm. Kreideformat. :

II, Weissenberg. u. Malnitz. Schicht.,
p. 134, fig. 123.

Description.—Shell moderately compressed, oblique, oval or rounded-oblong,
higher than long. Antero-dorsal border rather long and roughly parallel to the
slightly curving postero-ventral border; both curve gradually and regularly to
join the posterior border. Postero-dorsal shorter than the antero-dorsal border.
Umbones inconspicuous, close together. Apical angle about 100°. Ears small, of
nearly equal size, the posterior with three or four small radial ribs and with growth-
ridges. Anterior area moderately large, slightly convex except near the umbones,
smooth or with a few small ribs at the sides.

Ornamentation consists of 20 to 23 ribs. Those on the antero-ventral region
are strong and roof-like, and, in old specimens, bear a smaller rib on each
side; posterior to this region the ribs become much smaller and less elevated,
some being almost linear and with broad and nearly flat interspaces. At the
bottom of the furrows and in the middle of the flat interspaces there is a linear
rib. In well-preserved specimens very fine radial ribs and concentric lines
are seen.

34 CRETACEOUS LAMELLIBRANCHIA.

Measurements :

(1) (2) (3)
Length A 35 : 30 : 30 mm.
Height ; 31 : 28 : 20 2,
Thickness : 18 ; LZ, : 16

3)
(1, 2) Rye Hill Sands, Warminster.
(3) Upper Greensand, Longbridge, Devizes.

Afjjinities—This species is closely allied to Lima parallela, but is distinguished
by being less convex (especially in the region of the umbones), by being rather
shorter and higher, and by the ribs decreasing in size rather more rapidly when
traced from the antero-ventral region to the posterior region. The fine radial orna-
mentation is also perhaps rather better marked than in L. parallela.

L. intermedia differs from L. elongata (see below) in being less convex, relatively
shorter, in the ribs being less elevated and decreasing in size posteriorly, and in the
absence or indistinct character of the ribs on the anterior area.

It is also relatively shorter and higher than Lima gaultina, and the ribs on the
posterior half are much smaller and have broader and flatter interspaces. The
intermediate rib is distinct in L. intermedia, but is absent or indistinct in L. gaultina.

T'ype.—From the Cenomanian of Le Mans.

Distribution—Upper Greensand (zoue of Pecten asper) of Longbridge, near
Devizes. Rye Hill Sands of Warminster.

Lima (Manrettum) ELoncara (Sowerby), 1827. Plate VI, figs. 5, 6a—c, 7a, b.

1822. Puacrosroma, G. Mantell. Foss. 8. Downs, p. 129, pl. xix, fig. 1.
827 — gLonGATA, J. de C. Sowerby. Min. Conch., vol. vi, p. 118,
pl. dlix, fig. 2 (lower figure).
21847. Lia Astreriana, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ili, p. 549,
pl. cecexx, figs. 4—7.

1850. PuacrosroMA PARALLELUS, J. de C. Sowerby in F. Dixon. Geol. Sussex,
p- 356 (p. 386, ed. 2), pl. xxviii, fig. 16.

1854. Lia eLoneata, J. Morris. Cat. Brit. Foss., ed. 2, p. 171 (partim).

1869. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matéx. Pal. Suisse, ser. 5), p. 168.
1870. — — F. Rimer. Geol. yon Oberschles., p. 343, pl. xxix, fig. 1.
? 1876. — H. Deicke. 'Tourtia von Miilheim a. d. Ruhr, p. 27.
21877. — — G. Bohm. Geitschr. d. deutsch. geol. Gesellsch., vol. xxix
p. 234.
1897, — _— R. Leonhard. Kreideformat. in Oberschles. (Paleonto-
graphica, vol. xliv), p. 47.
1904, — — E. T. Newton and A. J, Jukes-Browne. Cret. Rocks of

Britain, vol. ii, p. 451.

LIMA. 35

Non 1836. Lima enonaara, A. Goldfuss. Petref. Germ., vol. ii, p. 87, pl. cii, fig. 13
(L. Minsteriana, VOrbigny).
F. A, Rimer. Verstein. nord-deutsch. Oolith.-geb., p. 79,
pl. xiii, fig. 11 (L. longa, Romer, 1841).

?— 18414. — a F. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p. 56.
— 1845. — — FE. Forbes. Quart. Journ. Geol. Soe., vol. i, p. 248 (L.
parallela, Sowerby).

P— 1846. — —— A. EH. Reuss. Die Verstein. der bohm. Kreideformat., pt. 2,
p- 33, pl. xxviii, fig. 6, non 9 (= DL. Reussi,
d’Orb.).

— 1863. — — A. v. Strombeck. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xv, p. 104 (ZL. Schmeisseri,
Wollemann).

?— 1872, — — H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto-

graphica, vol. xx, pt. 2), p. 40, pl. ix,
figs. 9, 10.

?— 1877. — — A. Fritsch. Stud. im Gebiete der bihm. Kreideformat. :
II, Weissenberg. u. Malnitz. Schicht., p. 132,
fig. 116.

Description.—Shell of moderate convexity, subquadrangular or nearly oblong,
rounded anteriorly, much longer than high. Antero-dorsal margin long, nearly
straight, and nearly parallel with the postero-ventral margin; postero-dorsal
margin short, nearly straight. Apical angle about 100°. Umbones sharp, close
together. Ears of moderate size. Anterior area large, the dorsal part slightly
concave, ornamented with from five to seven fairly strong ribs which are crossed
by fine growth-ridges.

Ornamentation consists of 19 or 20 very strong ribs, with sharp, and some-
times (especially on the dorsal part of the shell) slightly serrate summits. The
ribs have usually at their summits a distinct ridge with a shallow furrow on each
side, which sometimes gives rise to the appearance of a ridge on each side of the
rib. The grooves between the main ribs are deep, rounded, distinctly limited, and
of about the same width as the ribs. On the dorsal portions of the shell fine radial
ribs occur on both ribs and grooves; on the ventral portions they are not seen.
Fine concentric growth-lines cross both ribs and grooves, and some few (at
intervals) are more distinct.

Measurements :

(1) (2) (3) (4) (5) (8)
Length : 34 27 26 25 24, 24 mm.
Height : 24 18 20 20 18 | mae
(1. 3, 5, 6) Chalk Marl, Folkestone.
(2) H. subglobosus zone, Stoke Ferry.
(4) Chalk Marl, Ventnor.

36 CRETACEOUS LAMELLIBRANCHIA.

Affinities.
distinguished (1) by the stronger ribs on the anterior area, (2) by the grooves being

This species agrees in form with Lima gaultina (p. 31), but is

relatively broader and more distinctly limited, (3) by the ribs being more elevated,
(4) by the fine radial ribs being usually indistinct except on the dorsal portions of
the shell.

The form from the Pliner-kalk (Turonian) of Saxony figured as Jima
elongata by Geinitz seems to differ from this species in having fewer and more
rounded ribs, and in the ribs being more widely separated on the posterior part of
the shell than elsewhere. Similar remarks apply to the specimen figured by
Fritsch. Without the opportunity of comparing specimens I am unable to give a
definite opinion as to the Turonian form being distinct from L. elongata.

Lima Astieriana, a Orbigny, is perhaps identical with L, elongata, but the summits
of the ribs appear to be somewhat more rounded.

Tima Reussi, VOrbieny (L. elongata of Reuss) seems to differ from L. elongata
in having a smaller apical angle.

Remarks.—Under the name Plagiostoma elongata Sowerby figured two species.
It seems advisable to retain the name elongata for the one shown in the lower of his
two figures, since that form had been previously figured and described (but without
a specific name) by Mantell, and Sowerby refers to Mantell’s figure as an example
of Plagiostoma elongata.

Types.—I have not seen the specimen figured by Mantell. Sowerby’s type,
from the Chalk Marl of Hamsey, and also the specimen figured in Dixon’s work are
in the British Museum.

Distribution.—The range is from the Chloritic Marl to the zone of Holaster sub-
globosus. Chloritic Marl of Eastbourne and the Isle of Wight. Chalk Marl of
Ventnor, Folkestone, and Prince’s Risborough. Totternhoe Stone of Arlesey.
Zone of Holaster subglobosus of Blue Bell Hill (Burham), Stoke Ferry, and
Hunstanton.

Liwa (MANTELLUM) ELONGATA, var. ECHINATA, Htheridge, 1881. Plate VI, figs. 8, 9 a—e.

1881. Lima ecuinata, R. Etheridge. In Penning and Jukes-Browne, Geol. Cam-
bridge, p. 144, pl. ii, fig. 2.

Remarks.—The examples described by Etheridge as Lima echinata agree
perfectly in form, in size, and in the number and character of the ribs with L.
elongata, but on the ridge at the summit of each rib there is a row of short spines
which are frequently rounded and stumpy, and on each side of the rib (outside the

LIMA. 37

shallow groove mentioned in the description of Li. elongata) there is another row of
similar, but slightly smaller spines. In the furrows between the main ribs there
are transverse ridges.

On account of the close resemblance in the form and ribbing of L. echinata
to L. elongata, and also from the fact that in some specimens of the former the
ornamentation of the ribs is absent from a part of the shell and the ribs are then
indistinguishable from those of L. elongata, I am led to consider Ly. echinata as not
more than a variety of L. elongata. Further, in some specimens of J. elongata the
summits of the ribs are serrate.

[elongata var. echinata presents some resemblance to L. Schmeisseri, Wollemann,!
from the hotomagensis-Pliner of Limebure.

Types.—In the Sedewick Museum, from Burwell.

Distribution—Totternhoe Stone (Holaster subglobosus zone) of Burwell and
Cherry Hinton. Also recorded in the ‘ Geological Survey Memoirs’ from the zone
of Schlaenbachia varians.

Liwa (MANTELLUM) CANTABRIGIENSIS, nom. nov. Plate VI, figs. 10a, b, 11, 12.

1881. Lima ornara. RB. Etheridge. In Penning and Julkes-Browne, Geol. Cam-
bridge, p. 144, pl. iii, fig. 2 (non
ornata, d’Orbigny, 1847; non
ornata, Buvignier, 1852).

Description—Shell moderately conyex, oval or rounded-oblong. Anterior
margin rounded. Umbones and ears not seen.

Ornamentation consists of 16 or 17 main ribs with a few small ribs at the
posterior end. The anterior ribs are strong, roof-like, with ridged summits;
posteriorly the ribs become less prominent and the interspaces less depressed.
Both ribs and grooves are ornamented with fine, well-developed ribs, which are
closer together on the ribs than in the grooves; usually three or four occur on
each side of a main rib and three in each groove. Numerous concentric ridges
occur and give rise to spy projections where they cross the fine radial ribs.

Affinities—In form this appears to be similar to L. parallela (p. 28), but has
fewer ribs and is much more highly ornamented. The small rib at the bottom of
the grooye is not distinguishable from the other ribs.

It is more convex, has fewer ribs, and has the fine ornamentation better developed
than in L. intermedia.

Remarks.—This species is known by three specimens only. All are imperfect
near the umbo, but the fine ornamentation is well-preserved.

* Abhandl. d. k. preussisch. geol. Landesanst., N. F.,’ Heft 37 (1902), p. 55, pl. vii, fig. 9.

38 CRETACEOUS LAMELLIBRANCHIA.

On account of the name ornafa having been previously used by d’Orbigny and
by Buvignier for other species it is necessary to substitute some other name.

Types.—From the Cambridge Greensand (indigenous), preserved in the Sedgwick
Museum, Cambridge.

Distribution —Cambridge Greensand (indigenous). Lower Chalk of Burwell.

Lima (MANTELLUM) BRITANNICA, sp. nov. Plate VI, figs. 13 a—d.

1857. Lima evxaans, J. W. Salter. Quart. Journ. Geol. Soc., vol. xiii, p. 85, pl. ii,
fig. 3 (non elegans, Nilsson).

Description.—Shell moderately convex, sub-quadrate or nearly oblong, very
oblique. Antero-dorsal and postero-ventral margins more or less parallel; pos-
terior margin rounded. Wars of moderate size, with a few ribs on the inner
portions, and with distinct growth-lines; the anterior larger than the posterior
ear. Anterior area not distinctly limited, covered with ribs similar to those on the
rest of the valve but of nearly uniform size.

Ornamentation consists of eighteen main ribs, which are strong on the anterior
part of the shell, but become smaller in passing to the posterior end. At the
summit of each main rib is a narrow, elevated, secondary rib, and on each side of
a main rib are two or three similar but rather small ribs. The secondary ribs are
separated by broad and rounded furrows. The summits of the secondary ribs
are usually sharp and even, but occasionally slightly serrate.

Measurements :

Length : : ‘ ; : ‘ : : 19 mm.
Height : : : : : : : 2 ae

Affinities. This form, of which I have seen one example only, agrees with the
specimen preserved in flint from Moreseat (Aberdeenshire) which was described
and figured by Salter as Lima elegans (Nilsson). That specimen is now in the
Museum of Practical Geology. Nilsson’s! figure is scarcely sufficient to enable one
to determine the species, but from the recent illustrations given by Hennig? it is
seen that the British specimens differ from Lima elegans im beg more distinctly
oblong and especially in having more numerous secondary ribs.

i «Petrif. Suecana’ (1827), p. 26, pl. ix, fig. 7; Hisinger, ‘ Lethaa Suecica’ (1837), p. 55, pl. xv,
fie. 10.

2 Revis. Lamellibr. i Nilsson’s ‘ Petrif. Suecana’ (1897), p. 33, pl. ii, figs. 9, 10, 11, 24; Lima
elegans, Dujardin (‘Mém. Soe. géol. de France,’ vol. ii, 1837, p. 226, pl. xvi, fig. 1), is apparently

distinct from Nilsson’s species.

LIMA. 39

T'ype.—In the collection of Mr. R. M. Brydone.
Distribution.—Lower part of the zone of Micraster cor-anguinum of Seaford.

Lima (Manrectum) Retcuenpacut, Geinitz, 1839. Plate VI, figs. 14a, b, 15.

1839. Lima Rercuensacut, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 1, p. 24, pl. viii,

fig. 4.

1841. — Rercuensacuti, I’. A. Rimer. Die Verstein. d. nord-deutsch. Kreide-
geb., p. 57.

1843. — Rercuenpacut, H. B. Geinitz. Die Verstein. von Kieslingswalda,

p- 23, pl. v, fig. 9.
1846. — — A. EH. Reuss. Die Verstein. der béhm. Kreideformat.,
pt. 2, p. 34.
1847. — RercuEnpacutt, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ii, p. 544,
pl. cccexviui, figs. 1—4.
1850. — Reicuensacut, H. B. Geinitz. Das Quadersandst. oder Kreidegeb.

in Deutschland, p. 190.
== — Reicuensacutt, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 166.

1855. — — G. Cotteau. Moll. Foss. de ’Yonne, p. 101.

1867. — _ E. Guéranger. Album Paldéont. de la Sarthe, p. 19,
pl. xxiv, fig. 5.

1869. — Rercuensacut, & J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse,
ser. 5), p. 168.
1872, — c= H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal-
wontographica, vol. xx, pt. 1),
p- 208, pl. xliii, figs. 1, 2.
1876. — Reicuensacut, H. Deicke. Tourtia v. Miilheim a. d. Ruhr, p. 27.
1882. — Rercuensacut, P. de Loriol. Gault de Cosne, p. 101, pl. xiii, fig. 5.

Description.—Shell convex, oblong, oblique, rounded ventrally ; antero-dorsal
margin long, nearly straight and almost parallel with the opposite margin. Height
considerably greater than length. Anterior area large, smooth, not depressed.
Ears rather small, the anterior somewhat larger than the posterior.

Shell ornamented with from seven to ten very strong ribs, which have rounded
summits and are separated by rounded grooves of about the same width as the
ribs. Small and narrow radial ribs are present on both ribs and grooves.

Measurements :

(1) (2) (3)
Length : 29 25 21 mm,
Height ‘ 35 : 54. ; LV
Thickness : 19 : 16 : — 5,

(1—3) Cenomanian, Wilmington.

40 CRETACEOUS LAMELLIBRANCHIA.

Remarks.—This species is easily distinguished by the very strong radial ribs.
The English specimens, which at present are known from three localities only, are
not well-preserved, so that the details of the ornamentation cannot be seen clearly.

The occurrence of L. Reichenbachit in England (from Wilmington) was first
noted by Mr. Jukes-Browne in 1898. The only specimens which I have seen are
now in the Museum of Practical Geology and the Sedgwick Museum.

T'ypes.—From the Lower Pliner (Cenomanian) of Plauen near Dresden.

Distribution—Upper Greensand (zone of Pectew asper) of Warminster.
Chloritic Marl of Chard. Cenomanian Sandstone of Wilmington.

Lima (Manvetium), sp. Plate VI, fig. 16a, b.

Remarks.—A small specimen in the Museum of Practical Geology (No. 7896)
is similar in form and in the general character of its ornamentation to L. caita-
brigiensis (see p. 37), but the main ribs are not so strongly developed, the
interspaces are flatter, and the intermediate ribs are more prominent. It differs
from L. intermedia in its more distinctly oblong form and in the occurrence of
well-developed intermediate ribs.

This specimen resembles closely the lowest of the three figures referred to Lima
elegans by Guéranger."

Distribution.—Chloritic Marl of Chardstock.

Sub-genus—Crunoiwes, H. and A, Adams, 1858 (ex Klein, 1753).
(‘Genera of Recent Mollusca,’ vol. ii, p. 557).

Lima (Crenotves) rapa, d’Orbigny, 1847. Plate VI, figs. 17a—c. Plate VII, fig. 1.
Text-fig. 6.

1847. Tama rapa, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 546, pl. eecexix,
figs. 1—4.,
1850. — —— A. d'Orbigny. Prodr. de Pal., vol. 1, p. 166.
— - — H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutsch-
land, p. 188.
1855. — — G. Cotteau. Moll. Foss. de l’'Yonne, p. 101.
1867. — — EF. Guéranger. Albwn Paldéont. de la Sarthe, p. 19, pl. xxiv,
figs. 16, 17.

= ~ ——

1 «Album Paléont. de la Sarthe’ (1867), p. 18, pl. xxiv, fig. 1.

LIMA. 4]

1869. Lima rapa, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser. 5),
p- 168.
1871. Raputa (Crenorpes) rapa, F. Stoliczka. Paleont. Indica, Cret. Fauna
S. India, vol. iii, p. 414.
1872. Lima rapa, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palazontographica,
vol. xx, pt. 1), p. 206, pl. xliii, fig. 4.

Description.—-Shell moderately and regularly convex, with ovate outline, nearly
equilateral, considerably higher than long, margins evenly rounded. Umbones
small, pointed, close together. Apical angle about 85°. Ears rather large, much

Fia. 6.—Lima (Ctenoides) rapa, VOrbigny. Upper Greensand, Haldon. British Museum, No, L. 15616.
Interior of right valve. Natural size.

higher than long, with fine radial ribs; the anterior ear larger than the posterior,
the latter with its outer angle obtuse.

Ornamentation consists of numerous fine radial ribs which diverge slightly from
a median or nearly median line or sometimes in places from two lines. These ribs
are slightly raised and rounded, and are separated by very narrow grooves ;
near the anterior and posterior margins the ribs become much narrower and
sharper, and may bear small pointed projections. The ribs are slightly wavy
and their course is often more or less sharply deflected where they pass the
growth-lamellz. Numerous fine linear concentric ridges occur, and also some
growth-lamell.

4.2 4 CRETACEOUS LAMELLIBRANCHIA.

Measurements :

(1) (2) (3)
Length ; 66 : 45 : 30 mm.
Height ; 90 ; 59 : 41 ,,

(1—3) Upper Greensand, Haldon.

Affinities.—L. rapa is closely related to L. divaricata (p. 44) but the valves
are less flattened and the anterior part slopes gradually to the margin; the outline
is more regularly ovate, and the anterior and posterior ribs are much narrower
than the others. J. rapa is usually considerably larger than L. divaricata.

Types.—From the Cenomanian of Coudrecieux and Le Mans.

Remarks.—The presence of this species in English deposits appears to have
been recognised first by the late Mr. C. J. A. Meyer; it was recorded by Mr.
Jukes-Browne in 1896.

Distribution.—Upper Greensand of Haldon. Cenomanian (Meyer’s Bed 10) of
Dunscombe.

Lima (Crenoipes) tects, Goldfuss, 1836. Plate VII, figs. 2, 3.

1836. Lima recra, A. Goldfuss. Petref. Germ., vol. ii, p. 91, pl. civ, fig. 7.

1837. — rronposa, F. Dujardin. Mem. Soc. géol. de France, vol. ii, pp. 216,
227, pl. xvi, fig. 10.
1839. — sametiosa, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 1, p. 23.
1841. — vecra, F. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb., p. 58.
1847, — — A.dOrbigny. Pal. Franc. Terr. Crét., vol. iii, p. 547, pl. eccexix,
figs. 5—8.
1850. — — H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutsch-

land, p. 188.
— — — A.dOrbigny. Prodr. de Pal., vol. ii, pp. 166, 247.
— — ?, A. Alth. Geogn.-pal. Beschreib. Umgeb. v. Lemberg
(Haidinger’s Naturwiss. Abhandl., vol. iii,
pt. 2), p. 243.

Pisses = — ?, R. Kner. Denkschr. d. k. Akad. Wissensch. Math.-nat.
Cl., vol. iii, p. 318, pl. xvii, fig. 7.
1867. — — £. Guéranger. Album Paléont. de la Sarthe, p. 19, pl. xxiv,
fig. 11.
1869. — — Ff. Favre. Moll. Foss. de la Craie de Lemberg, p. 135.
1869-70. - — F.J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix

(Matér. Pal. Suisse, ser. 5),
pp- 168, 170, 173.

1871. Rapuxa (Crenoipes) Tecra, F. Stoliczka. Paleeont. Indica, Cret. Fauna
8. India, vol. ii, p. 420,
pl. xxx, fig. 12.

LIMA. 4s

ed

1872. Lima recra, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleontographica,
vol. xx, pt. 1), p. 206, pl. xliii, fig. 3.

1877. > — — A. Fritsch. Stud. im Gebiete der béhm. Kreideformat.: II,
Weissenberg. u. Malnitz. Schicht., p. 130, fig. 113.
1894. — — 8B. Lundgren. Mollusk-faunan i Mammillatus och Mucronata

zonerna (K. Svenska Vet.-Akad. Handl.,
vol. xxvi, No. 6), p. 43.

1895. — — F. Vogel. Hollandisch. Kreide, p. 18.
— — cf. rrcra, H. Tiessen. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlvii,
p. 474.
1898. — ecra, G. Miller. Mollusk. Untersen. v. Braunschweig u. Ilsede, p. 27.
1902. — — M. v. Palfy. Mittheil. a. d. Jahrb. d. k. ungarisch. geol.

Anstalt, vol. xiii, p. 275, pl. xx, fig. 5.

Description—Shell convex, much flattened, sub-ovate, slightly oblique,
considerably higher than long; antero-dorsal part sloping steeply to the antero-
dorsal margin which is rather long and straightened. Umbones small, only slightly
incurved. Lars rather large, relatively high, the anterior larger than the posterior.

Ornamentation consists of numerous small radial ribs, which are rounded, and
smooth or nearly smooth. At fairly regular intervals the course of the ribs is
interrupted by strong growth-lamelle, ventrally to which the direction of the ribs
is sometimes deflected. Growth-lamellx, and sometimes ribs, are present on the

ears.
Measurements :
Length : . 5 : : : : : 27 mm.
Height 3h ie

From the Cenomanian (Bed 11) of Dunscombe.

Affinities —This species is related to L. divaricata (see p. 44), but is
distinguished by the growth-lamellz, by the ribs not diverging from a median
line, and by the absence of the fine concentric ridges. Lima essertensis, de Loriol,'
from the Urgonian, is a similar form but is distinguished by the growth-lamell
being more closely placed.

Remarks.—This species has a considerable stratigraphical range, extending
from Lower Cenomanian to Senonian. It has been recognised in France, Holland,
Scandinavia, Saxony, Bohemia, Hungary, ete. In England it has been found in
the Cenomanian of Devon only, having been discovered and identified by the late
Mr. C. J. A. Meyer, and first recorded by Mr. Jukes-Browne. The examples from
the Arrialoor Group, described by Stoliczka, seem quite indistinguishable from the
European forms.

1 « Foss. Corall. Valang. et Urgonien de Mt. Saléve ’ (1866), p. 83, pl. v, fig. 12; also in A. Favre,
‘Recherch. géol. Savoie,’ vol. i (1867), p. 388, pl. c, fig. 23; Pictet and Campiche, * Terr. Crét. Ste.
Croix’ (1869), p. 139, pl. elxiii, fig. 7.

th CRETACEOUS LAMELLIBRANCHIA.

Types.—From the Senonian of Maestricht. D’Orbigny’s specimens came
from the Cenomanian of Le Mans and from the Senonian of Tours and Loir-et-
Cher.

Distribution —Cenomanian (Bed 11) of Dunscombe.

Lina (Crenomes) pivaricata, Dujardin, 1837. Plate VII, figs. 4a—d, 5, 6a, b.

1837. Lima pivaricara, F. Dujardin. Mém. Soe. géol. de France, vol. ii, p. 227,
pl. xvi, fig. 7.

1840. — arcuara, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 2, p. 57, pl. ix, fig. 7.

1841. — _ pivaricara, F. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p- 58.

1850. — — A, dOrbigny. Prodr. de Pal., vol. ii, p. 248.

— — aranosa, J. de C. Sowerby in F. Dizon. Geol. Sussex, p. 347 (p. 382,
ed. 2), pl. xxviii, figs. 24, 2
1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 171.
1859. Myzinus? specraniuis, J. Miller. Petref. der Aachen. Kreidef., supple-
ment., p. 10, pl. vii, fig. 10.
1870. Lima aranosa, F’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix.
(Matér. Pal. Suisse, ser. 5), p. 169.
— — pivanricara, Pictet and Campiche. Ibid., pp. 171, 173.
1871. Rapuna (Crunoipes) Granosa, FI’. Stoliczka. Paleont. Indica, Cret.
Fauna S. India, vol. iii, p. 415.
— — — pivaricaTa, Stoliczka. Ibid., p. 415.
1872. Lima pivaricara, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal-
wontographica, vol. xx, pt. 1),
p. 205, pl. xlii, fig. 18.
1889. — — A. Fritsch. Stud. im Gebiete der bohm. Kreideformat. :
IV, Teplitz. Schicht., p. 83, fig. 77.
—- — -- EF. Holzapfel. Die Mollusk. Aachen Kreide (Paleon-
tographica, vol. xxxv), p. 241,

2
5

pl. xxvii, fig. 7.
1897. — aranosa, H. Woods. Quart. Journ. Geol. Soce., vol. liii, p. 383.
1902. -—— pivaricara, M. v. Pilfy. Mittheil. Jahrb. d. k. ungarisch. geol.
Anstalt, vol. xiii, p. 274, pl. xx, fig. 4.

Description.—Shell convex, flattened, the anterior marginal part sloping
steeply, the posterior part more gradually; outlme rather variable, more or less
ovate or approaching to oblong, considerably higher than long, only slightly
unsymmetrical. Umbones rather small, not much incurved. Kars relatively
short and high, not sharply limited; the anterior larger than the posterior.

Ornamentation consists of numerous small radial ribs which diverge from a
median or nearly median line or sometimes in part from two lines forming an

LIMA. 45

inverted W. The ribs are slightly raised and often somewhat Wavy or irregular,
especially near the growth-ridges. The ribs and grooves are crossed by numerous
concentric linear ridges. The ribs are sometimes nodular, the nodules having a
concentric arrangement. At intervals, usually rather distant and fairly regular,
distinct growth-lamellz are seen.

Measurements :

(1) 2) (3)
Length : 37 20 22 mm.
Height : ol Bit : By Aner

(1) Chalk, Newtimber.
(2) B. mucronata zone, Norwich.
(3) H. planus zone, Dover.

Affiiities—See Th. (Ctenoides) rapa (p. 42) and L. (Ctenoides) tecta (p. 45).
L. divaricata also presents some resemblance to Lima Holzapfeli, Hennig,' found
in the Danian of Faxe.

Remarks.—This species has hitherto been known in England as Lina granosa,
Sowerby. After making a careful comparison I feel no hesitation in regarding
it as identical with the widely-distributed L. divaricata, Dujardin. This form is
comparatively rare in England, and the part of the shell near the umbo is usually
wanting or imperfectly preserved.

Type.—From the Chalk (? Lower Senonian) of Touraine. Sowerby does not
mention the locality or the horizon from which he obtained Lima granosa, and I have
not succeeded in finding the type.

Distribution.—Zone of Terebratulina of Hitchin. Zone of Holaster planus of
Winchester, Dover, and Cheveley, Blue Bell Hill, Burham (? H. planus zone).
Chalk Rock of Cuckhamsley. Zone of Micraster cor-anguinum of Micheldever.
Zone of Actinocamax quadratus of Salisbury. Zone of Belemnitella mucronata of
Salisbury and Norwich.

Sub-genus—LIMAtvLa, S. V. Wood, 1839.
(‘ Mag. Nat. Hist.,’ new series, vol. iii, p. 233.)
Liva (Limatuta) Tompeckiana, d’Orbigny, 1847. Plate VII, figs. 7a, b, 8u—c, 9a, b.
1847. Lima Tomsbecxrana, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 534,

pl. cecexv, figs. 13—17.

1850. — _ d@ Orbigny. Prodr. de Pal., vol. ii, p. 82.

1 « Bih. K. Svenska Vet. Akad. Handl.,’ vol. xxiv, No. 7 (1899), p. 10, pl. i, figs. 1, 2; Ravn,
*Mollusk. Danmarks Kridtafl I. Lamellibr.’ (1902), p. 100, pl. ii, fig. 15.

46 CRETACEOUS LAMELLIBRANCHIA.

? 1854. Lima semisuucara, J. Morris. Cat. Brit. Foss., ed. 2, p. 172 (partim).

1855. — Tomprckrana, G. Cotteau. Moll. Foss. de ?Yonne, p. 100.

1861. — — P. de Loriol. Anim. Invert. Foss. Mt. Saléve, p. 95,
peo vives TUE

1869. — — P. de Loriol and V. Gilliéron. Urgon. infér. de

Landeron, p. 19, pl. i, fig. 17.
— — — F. J. Pictet and G. Campiche. -Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5), p. 148.

1871. Rapvuza (Limaruta) Tomprcxrana, F. Stoliczka. Paleont. Indica, Cret.

Fauna 8. India, vol. iii, p. 414.

— Lima Tompeckriana, W. A. Ooster. Protozoe Helvetica, vol. ii, pp. 104,
123, 140.

1883. — — W. Keeping. Foss., ete., Neoc. Upware and Brick-
hill, p. 111.

Description.—Shell oval, inflated, higher than long, produced a little more
anteriorly than posteriorly. Umbones rather small, close together. Kars equal.
Margins of valves rounded, the posterior with a greater curvature than the
anterior.

Ornamentation consists of from 13 to 16 strong, rounded or slightly keeled
ribs separated by narrow grooves. The ribs are confined to the median part of
the shell, and the anterior and posterior parts are without ribs. The ribbed portion
is not quite symmetrically placed, the anterior smooth portion being rather larger
than the posterior smooth portion. Very fine concentric ridges are present on the
shell, and may form scale-like projections where they cross the ribs.

Measurements :

(1) (2) (4) (5) (6)
Length 9 9 8 8 7 1 ‘mm:
Height 12 11 Zo) als 10 Loo"

(1—5) Hythe Beds, Court-at-Street.
(6) Lower Greensand, Brickhill.

Affinities—Some specimens of L. T'ombeckiana approach very closely L.
Fittont from Blackdown and Haldon (see p. 48), and it is quite possible that the
latter is only a local variety of the former since some examples found in the Upper
Greensand of Charmouth and Potterne (Plate VII, fig. 10) seem indistinguishable
from L. Tombeckiana. As arule L. Tombeckiana differs from L. Fittoni in having
the ribbed part of the shell more nearly symmetrical in position, in the shell being
rather longer and rather more convex with the umbonal part more pointed, and
in the ribs being more rounded.

L. Tombeckiana differs from L. senisulcata, Nilsson, in being smaller, relatively
longer, less symmetrical, and with the umbonal part more pointed. In this con-
nection, however, it should be noted that Hennig! considers that specimens which

1 Revis. Lamellibr. i Nilsson’s ‘ Petrific. Suecana’ (1897), p. 29.

LIMA. 47

he has seen from the Lower Greensand of Atherfield and Blackgang belong to
L. semisuleata. L. Tombeckiana also resembles L. suprajwrensis, Contejean,' found
in the Upper Jurassic.
Types.—D’Orbigny does not give the locality of the type, but says that he
obtained specimens from the Neocomian of Neuchatel, Auxerre, Saint Sauveur, ete.
Distribution —Hythe Beds of Court-at-Street near Lympne. Lower Greensand
of Brickhill. Tealby Limestone (zone of B. brunsvicensis) of North Willingham.

Lima (Limatuta) Durrintana, @Orbigny, 1847. Plate VII, figs. 11 a—e.

? 1845. Lima semisutcata, EL. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 248
(non semisuleata, Nilsson).

1847. Lima Duprntana, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 535,
pl. eecexv, figs. 18—22.

1850. = — @Orbigny. Prodr. de Pal., vol. ii, p. 81.

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 171.

1855. — — G. Cotteau. Moll. Foss. de l’Yonne, p. 100.

1865. — -— H. Coquand. Mon. Aptien de l’Espagne, p. 151.

1869. — a F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse,

ser. 5), p. 150.
1871. Rapuna (Limaruta) Duprniana, F. Stoliczka. Paleont. Indica, Cret.
Fauna 8. India, vol. ili, p. 414.

Non 1883. Lima Duprnrana, A. Fritsch. Stud. im Gebiete der bbhm. Kreideformat. :
III, Iserschichten, p. 112, fig. 81.

Deseription—Shell oval, moderately convex, much higher than long, nearly
equilateral, with the posterior margin more convex than the anterior. Umbones
very small, pointed, close together. Ears unequal.

Ornamentation consists of from ten to fourteen very narrow radial ribs,
usually with sharp summits, separated by broad rounded grooves. The anterior
and posterior parts of the shell are without ribs, and the posterior part is con-
siderably larger than the anterior. Very fine concentric ridges are present.

Measurements :

(1) (2)
Length F 11 - 8 mm.
Height ; PA . (aomees

(1) Tealby Limestone, North Willingham.
(2) Ferruginous Sands, Shanklin.

1 «Kimmérid. de Montbéliard’ (1859), p. 351, pl. xxvii, fig. 9; de Loriol and Cotteau, ‘ Portland.
de l’ Yonne’ (1868), p. 205, pl. xiv, figs. 1, 2.

48 CRETACEOUS LAMELLIBRANCHIA.

Affinities. —This species is easily distinguished from L. Tombeckiana (see p. 45)
by its relatively higher and less inflated form, by the narrow ribs, and by the less
symmetrically placed ribbed area.

In its narrow ribs L. Dupiniana resembles L. subequilateralis, @Orbigny (see
page 49) but the ribs in the latter are distributed over the greater part of the
shell and are more widely separated and more numerous.

The specimens referred to L. semisulcata by Forbes are poorly preserved, but
probably belong to this species.

1'ypes.—From the Neocomian of Marolles (Aube) and Saint Sauveur (Yonne).

Distribution.—Tealby Limestone (zone of B. brunsvicensis) of North Willing-
ham. Ferruginous Sands of Shanklin. Atherfield Beds of Redhill. Hythe Beds
of Hythe (fide Topley).

Lima (Limatruta) Frrront, d’Orbigny, 1850. Plate VII, figs. 12—14, 15 a—e.

1836. Lima semrsuncara, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp. 336, 359 (not 129, 158), pl.

xi, fig. 10.
1850. — Frrront, A. d’Orbigny. Prodr. de Pal., vol. 11, p. 82.
1854. — semisuncata, J. Morris. Cat. Brit. Foss., ed. 2, p. 172 ( partim).
1869. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matcr. Pal. Suisse,
ser. 5), p. 166 (partim).

Description.—Shell oval, moderately convex, higher than long, slightly in-
equilateral, with rounded margins, the posterior being more convex than the
anterior. Umbones small, close together. Hars equal.

Ornamentation consists of from 13 to 15 radial ribs with sharp summits,
separated by narrow grooves. Pointed projections are present on the summits
of the ribs, especially near the ventral border of the shell. The anterior and
posterior parts of the shell are without ribs. The ribbed area is unsymmetri-
cally placed, and the anterior smooth part of the shell is considerably smaller
than the posterior part. [Fine concentric ridges are seen on well-preserved

specimens.
Measurements :
(1) (2) (3) (4) (5) (6) (7)
Length . 10 9 8 8 C ‘t 6 mm.

Height. 16 14. 14 13 epee MQ), - 5
(1, 3—7) Upper Greensand, Haldon.
(2) nae * Blackdown.

LIMA. 49

Affinities —This form was referred by Sowerby (in Fitton) to the Senonian
species L. semisulcata, Nilsson,! but has been regarded by most later writers as
distinct from that species, and was named L. Fittoni by d’Orbigny.

L. Fittom differs, as a rule, from L. semisulcata in its smaller size, and in having
the ribbed area less extensive and much more asymmetrical in position, though
occasionally, however, it is nearly symmetrical. It also appears to differ in
having a relatively shorter hinge-line and less equilateral form.

For the relation of L. Fittoni to L. Tombeckiana see p. 46.

T'ype.—The type is Lima semisuleata, Sowerby (non Nilsson) from the Upper
Greensand of Blackdown. A specimen in the Bristol Museum is regarded as the
type, but does not agree very well with the figure.

Distribution —Upper Greensand (zone of Schlanbachia rostrata) of Blackdown
and Haldon. Cenomanian of Axmouth (Bed 12 of Meyer), Dunscombe (Bed 10),
and Pinhay.

Lora (Limatuta) supzQuiiaTErRaLis, d’Orbigny, 1847. Plate VII, figs. 16a, b, 17.

1847. Tima supmquivaterALis, A. d’Orbiqny. Pal. France. Terr. Cret., vol. iii,
p- 558, pl. eecexxiii, figs. 1—5.
1850. — — d’Orbigny. Prodr. de Pal., vol. ii, p. 167.
1870. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal. Suisse,
ser. 5), p. 169.
1871. Rapota (Limaruna) supmQurinaTERatis, I. Stoliczka. Palweont. Indica,
Cret. Fauna 8. India, vol. iii,
p. 415.

Description —Shell oval, or rounded oblong, pointed at the umbones, nearly
equilateral, about twice as high as long, of moderate convexity. Anterior margin
less curved than the posterior. Hars equal, smooth, with pointed ends.

Ornamentation consists of about 20 very narrow ribs separated by broad,
slightly concave, interspaces which are crossed by growth-lines. Ribs are absent
near the anterior and posterior margins.

Measurements :

Length ; : : ; 10 mm.
Height : : : : 19»-;.

Upper Greensand, Warminster.

Affinities —See Lima Dupiniana (p. 48) and Lima sp. (p. 52).
Remarks.—I have seen only two English examples of this species, both of

1 For references, see p. 51, footnote,

~

50 CRETACEOUS LAMELLIBRANCHIA.

which are more or less imperfect, but after an examination of specimens of
L. subequilateralis from Le Mans in the Museum of Paleontology at Paris I am
inclined to refer them to that species. In the specimens from Le Mans the
number of ribs is sometimes greater than is shown in D’Orbigny’s figure, also the
ears may be less sharply separated from the valve, and in one case the hinge-line
was seen to be relatively longer.

Types.—From the Cenomanian of Le Mans. ‘The specimens here figured are
in the British Museum.

Distribution—Upper Greensand (zone of Pecten asper) of Warminster.

Lima (Limatuna) pecussata, Goldfuss, 1836. Plate VII, figs. 18a, 6, 19, 20a, b.

1836. Lima prcussara, A. Goldfuss. Petref. Germ., vol. ii, p. 91, pl. civ, fig. 5.
1837. Puacrosroma Granutatum, W. Hisinger. Letheea Suecica, pl. xv, fig. 7.
1841. Lrma precussata, fF. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,

p. 55.
1846. — A. E. Reuss. Die Verstein. der bohm. Kreideformat.,
pt. 2, p. 32, pl. xxxviii, fig. 15.
1847. — smmisuncata, J. Miiller. Petref. der Aachen. Kreidef., pt. 1, p. 33.
1850. — ovxcussara, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 248.

— — spmisuntcata, R. Kner. Verstein. v. Lemberg (Haidinger’s Natur-
wiss. Abhandl., vol. iii, pt. 2), p. 29.

oo —- pecussata, A. Alth. Geogn.-paleont. Beschreib. v. Lemberg (Haid-

inger’s Naturwiss. Abhandl., vol. iii, pt. 2),

p. 241.
— — semisuncaTa, Alth. Ibid., p. 242.
1863. — opercussata, A. v. Strombeck. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xv, p. 151.
> — — — S. Placketko. Das Becken von Lemberg (Jahresb. d.

k. zweite Ober-Gymnas. in Lemberg),
p. 20, pl. i, fig. 19.

1866. — — K. A. Zittel. Die Bivalven d. Gosaugeb. (Denkschr. d.
k. Akad. d. Wissensch. Wien, vol. xxv),
pt. ii, p. 105, pl. xvi, fig. 4.

1869. — -- E. Favre. Moll. Foss. de la Craie de Lemberg, p. 136.

1870. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5),
p. 174.

1871. Raputa (Limaruna) pecussara, F. Stoliczka. Paleont. Indica, Cret.
Fauna 8. India, vol. i, p. 415.
1888. Lrma pecussara, A. Peron. LL’ Hist. du Terr. de Craie, p. 145, pl. i, fig. 18.
1889. — -- EH. Holzapfel. Die Mollusk. Aachen. Kreide (Palion-
tographica, vol. xxxv), p. 242, pl. xxvii,

fig. 4.

LIMA. 5]

1900. Lima prcussata, C. Gageland F. Kaunhowen. Jahrb. d. kk. preussisch. geol.
Landesanst. fiir 1899, p. 232.
1902, — -—— J.P. J. Ravn. Mollusk. i Danmarks Kridtafl.: I. Lam-
ellibr. (IX. Danske Vid. Selsk. Skrift.,
6 Rekke, nat. og. math. Afd., vol. xi),

p: 96, pl. ii, fig. 11.
- A. Wollemann. Fauna d. Liimeburg. Kreide (Abhandl.
d. k. preussisch. geol. Landesanst.,

N. F., Heft 37), p. 57.

Description.—Shell inflated, ovate or rounded-oblong, nearly equilateral. Um-
bones small. Kars rather small, nearly equal.

Ornamentation consists of numerous sharp ribs, separated by narrow grooves.
The ribs become less distinct on the anterior and posterior parts of the shell.
Numerous fine concentric ridges occur, and sometimes give rise to a tubercular
appearance on the summits of the larger ribs.

Measurements :

(1) (2) (3) (4) (5)
Length . 10 9 7 7 6°5 mm.
Height . 13°5 12 ll 10°5 GD ags

(1, 2, 4, 5) A. quadratus zone, East Harnham.
(3) Uintacrinus band, Devizes Road, Salisbury.

Affinities. —L. semisulcata, Nilsson,’ is distinguished from L. decussata by the
ribs being limited to the median part of the shell, and by the relatively higher
valves.

Peron thinks that L. pectinata, @Orbigny, may be only a variety of L. decussata.
It appears to differ from the latter in having the ribs more tubercular and usually
fewer in number.

T'ype.—From the Senonian of Rinkerode, near Miinster.

Distribution —Uintacrinus band of Devizes Road, Salisbury. Zone of Actino-
cama quadratus of Kast Harnham and Ashley Hill. Zone of Belemnitella mucronata
of Clarendon.

Lima (LIMATULA) WINTONENSIS, sp. nov. Plate VII, figs. 21a, b, 22a—d.

Description—Shell inflated, ovate, nearly equilateral, pointed dorsally.

Ornamentation consists of 15 or 16 strong, rounded ribs on the median part of
the valve only. The ribs are separated by very narrow grooves, and bear many

1 «Petrif. Suecana’ (1827), p. 25, pl. ix, fig. 3; Hennig, Revis. Lamell. i Nilsson’s ‘ Petrif.
Suecana’ (1897), p. 28, pl. ii, figs. 14, 17.

52 CRETACEOUS LAMELLIBRANCHIA.

strong ridges placed concentrically and regularly. Below a growth-ring the
ridges are sometimes situated more closely together. One or two ribs at the
margins of the ribbed area are rather smaller than the others. The parts between
the ribbed area and the anterior and posterior margins of the valve are smooth
except for fait growth-lines.

Measurements ;

@) 2) (3) (4) (5)
Length : 7 6 aw 5-5 5 mm.
Height : 10 8 8 a 7

(1) Chalk, Clayton.
5) A. quadratus zone, Winchester.

(2

Ajjinities—This species is distinguished from L. decussata (p. 50) by being
more pointed dorsally, by having fewer ribs, which also are rounded and confined
to the median part of the valve, and by the strong ridges which extend across the
ribs.

In outline this species resembles Lima pectinata, V@Orbigny,’ but differs im
having fewer ribs, in the absence of ribs on the anterior and posterior parts of the
valves, and in the ribs not being carinated and having ridges across them
instead of tubercles at the summits.

This species resembles closely the form figured by Geinitz* as L. semisuleata,
Nilsson.

Distribution.—Zone of Actinocamar quadratus of Winchester. Upper Chalk
(probably zone of Micraster cor-testudinarium) of Kenley.

Lima (Limatuta), sp. Plate VII, fig. 23a, b.

Description.—Shell inflated, oval, nearly equilateral. Umbones small. Hinge-
line relatively long. Kars not sharply limited, nearly equal.

Ornamentation consists of about 20 narrow ribs, separated by very broad and
shallow interspaces in which very fine radial ribs may be seen. The ribs anterior
to the median line are closer together and rather stronger than the others. On
the parts of the valves next to the ears ribs appear to be absent.

Measurements :

Length ; : ; : f : : : 6°5 mm.
Height ; : ; : : ; : : 9 =

' «Pal. Frang. Terr. Crét.,’ vol. iii (1847), p. 572, pl. eecexxvii, figs. 15—19.
2 «Das Elbthalgeb. in Sachsen,’ pt. 2 (1873), p. 53, pl. xvi, fig. 14.

cs
:

LIMA. 53

Affinities —In the character of its ornamentation this form resembles Lima sub-
ewquilateralis, dV Orbigny (see p. 49), from the Cenomanian of Le Mans, but the shell
is not so high, is less pomted in the umbonal region, and has a longer hinge-line.

In outline this form resembles the example figured by Ravn! as Lima Morch-
hammert, von Hagenow, but possesses a much larger number of ribs.

Remarks.—I have seen one specimen only, which is in Dr. Blackmore’s
collection.

Distribution.—Zone of Belemnitella mucronata of Clarendon (Salisbury).

Sub-genus—Limua, H. G. Bronn, 1831.
(‘Italiens Tertiir-Gebilde und deren Organische Hinschliisse,’ p. 115.)
Liwa (Limes?) composita (Sowerby), 1836. Plate VII, figs. 24a, b, 25a, b, 26.
1836. Prcren compositus, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,

pp. 241, 342, pl. xvii, fig. 20.
1847. Lima cenomanensts, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. i, p. 552,

pl. eecexxi, figs. 11—15.
505. — — d'Orbigny. Prodr. de Pal., vol. ii, p. 167.
1867. — -- E. Guéranger. Album Paléont. de la Sarthe, p. 19,
pl. xxiv, figs. 4, 9.
1870. — _ F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse,
ser. 5), pp. 161, 168.

1871. Linea — F. Stoliczka, Paleont. Indica, Cret. Fauna 8. India,
vol. ili, p. 416.
1882. Lia — R. Windméller. Jahrb. d.k. preussisch. geol. Landes-

anst. fiir 1881, pp. 24, 29.

Measurements :

(1) (2) (3) (4) (5) (6)
Length 115: 11 10 9 9 8 mm.
Height 15 13 11:5 10:25 10 95

(1, 3—6) Upper Greensand, Warminster.
(2) Rye Hill Sand, Maiden Bradley.

Affinities —This form is closely related to Lima granulata (see below). ‘The
ornamentation appears to have been similar in both cases, but in 1. composita the

scale-like spines on the ribs are much less perfectly preserved and usually appear
as tubercles only. In L. composita the shell appears to be rather less oblique and

1 «Molluskerne i Danmarks Kridtaflej. I. Lamellibr.’ (1902), p. 97, pl. ii, fig. 12.

54 CRETACEOUS LAMELLIBRANCHIA.

more nearly equilateral than in L. granulata; the height is also slightly greater
and the umbones rather more prominent; the ribs appear to be narrower and to
have sharper summits. The smaller convexity of L. composita mentioned by
@Orbigny does not seem to be constant.

Remarks.— An examination of the type of Pecten compositus, Sowerby, shows
that it is an example of this species (see Vol. I, p. 188, footnote), and con-
sequently the specific name composita must take the place of cenomanensis.

The French examples which I have seen are, on the average, larger than the
English.

Types.—The type of L. cenomanensis came from the Cenomanian of Le Mans.
The type of Pecten compositus is in the Bristol Museum; it is labelled
“ Blackdown ” but is not siliceous and is more probably from Warminster. _

Distribution.—Upper Greensand (zone of Pecten asper) of Warminster. Rye
Hill Sand of Maiden Bradley. I have not seen the specimens recorded in the
Memoirs of the Geological Survey from the zones of Schlanbachia varians and
Holaster subglobosus of Hunstanton.

Lima (Limza ?) Granubata (Nilsson), 1827. Plate VII, figs. 27a—c, 28, 29a, b.
5) 5) 5 > F) >

1827. Pxtaciostoma GranuLatum, S. Nilsson. Petrif. Suecana, p. 26, pl.
fig. 4.

1833. — GranuLosum, S. Woodward. Geol. Norfolk, pp. 48, 51,

pl. v, fig. 26.

1836. Lima Granunata, A. Goldfuss. Petref. Germ., vol. ii, p. 89, pl. ciii, fig. 5.

1837. PuagrosromMa GranuLatum, W. Hisinger. Letheea Suecica, p. 54 (not the
figure, pl. xv, fig. 7).

1841. Lima muricara, F. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,

p- 59.
1842. — qranubara, F. v. Hagenow. Neues Jahrb. fiir Min., ete., p. 559.
1846. — — A. E. Reuss. Die Verstein. der bébhm. Kreideformat.,
pt. 2, p. 32, pl. xxxviii, fig. 21.
1847, — = A. @Orbigny. Pal. Franc. Terr. Cret., vol. iti, p. 570,

pl. eecexxvii, figs. 5—9. (Named
L. granosa on plate.)

1850. — -- @ Orbigny. Prodr. de Pal., vol. ii, p. 248.

1851. — psEUDOCARDIUM, INFLATA ET DENTATA, J. Miiller. Petref. der Aachen.
Kreidef., pt. 2, pp. 67, 68.

1855. — q@ranuxata, G. Cotteau. Moll. Foss. de l’Yonne, p. 102.

1870. — a C. Schliiter. Neues Jahrb. fiir Min., ete., p. 950.

— — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Mat¢ér. Pal. Suisse,
ser. 5), p. 170.

LIMA. D5

1876. Limma oranutata, D. Brauns. Zeitschr. f. d. gesammt. Naturwiss.,
vol. xlvi, p. 386.
—— Lima aranuata, H. Deicke. Die Tourtia von Miilheim a. d. Ruhr, p. 27.
1881. Limra cranutara, K. A. Zittel. Handb. d. Paleont., vol. ii, p. 27.
1888. Lrma eranunara, A. Peron. WHist. Terr. de Craie, p. 147.
1889. Limea eranunata, O. Griepenkerl. Senon. von Konigslutter (Palsont.
Abhandl., vol. iv), p. 41.
— Lrwa aranvutosa, EB. Holzapfel. Die Mollusk. Aachen. Kreide (Paleon-
tographica, vol. xxxv), p. 239, pl. xxvii,
fig. 6.
= — GrRanuLata, A. Fritsch. Stud. im Gebiete der bbhm Kreideformat. :
IV, Teplitz. Schicht., p. 83, fig. 76.
1893. — —- Fritsch. Tbid., V, Priesener Schicht., p. 100.
1894. . — — B. Lundgren. Mollusk-faunan i Mammill. och Mucron.
zonerna (K. Svenska Vet.-Akad. Handl.,
N. F., vol. xxvi, No. 6), p. 42.
1897. — — A. Hennig. Revis. Lamell. i Nilsson’s ‘Petrific. Suecana’
(K. Fys. Siillsk. i Lund. Handl., N. F.,
vol. viii), p. 26, pl. ii, figs. 6—8.
1898. — — G. Miller. Mollusk. d. Untersen. v. Braunschweig u.
Ilsede (Abhandl. d. k. preussisch. geol.
Landesanst., N. F., Heft 25), p. 29, pl. iv,

: fig. 6.
90 — A. Wollemann. Jahrb. d.k. preussisch. geol. Landesanst.
fiir 1900, vol. xxi, p. 16.
1902. — — Wollemann. Limeburg. Kreide (Abhandl.d.k. preussisch.

geol. Landesanst., N. F., Heft 37), p. 57.

-- J. P. J. Ravn. Mollusk i Danmarks Kridtaflej. I. (K.
Danske Vid. Selsk. Skrift., 6 Rekke,

nat. og. math. Afd., vol. xi), p. 101.

Non 1837. — — F. Dujardin. Mém. Soe. géol. de France, vol. ii, p. 226,
pl. xvi, fig. 4 (= L. Meslei, Peron, 1888).

Description—Shell very convex, oval, slightly oblique, with rounded outline ;
height a little greater than length. Apical angle very large. Umbones small,
incurved, close together. ars of moderate size, nearly equal, rather low and
long, with a few spiny ribs.

Ornamentation consists of numerous (usually from 22 to 24) strong ribs with
sharp summits, separated by narrow furrows. Lach rib bears three rows of scale-
like spines, one row being at the summit and one on each side. The spines are
placed near together, at regular intervals, and curve upwards from the surface of
the shell, the terminal parts sometimes becoming quite erect. The middle row is
rather larger than the rows on the sides. In some cases the spines are represented
by granules. On the anterior and posterior parts of the shell the ribs may be

56 CRETACEOUS LAMELLIBRANCHIA.

smaller than elsewhere, but the middle rows of spines are here often relatively
larger.
Measurements :
Gd) (2) ©) (€) (5) (6) (7) (8) (9) (0) (11)
Length 19 16 15 11 10:4 0 10.8 95 16. *21 mam.
Heisht 21 18 16 12° Il 105. 1f 39 10 18 ?24
(1—5) B. mucronata zone, Norwich.
(6) » Alderbury.
(7) A. quadratus zone, East Harnham.

33

(8) B. mucronata zone, Clarendon.
(9—11) Chalk of Trimingham.

Affinities. —Vhe form from the Lower Senonian of 'Touraine described and figured
as Lima granulata by Dujardin, is regarded by Peron! as belonging to another
species which he names Lima Meslei. Peron states that [. Meslei differs from L.
granulata in haying more numerous ribs ornamented with fine granules of which
the middle row is not larger than the lateral rows; further, the ribs disappear on
the anterior and posterior parts of the shell, and the ears are without ornamen-
tation.

Radula scabricula, Stoliczka,? from the Arrialoor Group, is closely related to
Lima granulata, but owing to the imperfect preservation of the single valve on
which the species is founded, an exact comparison is not possible. The ornamen-
tation, however, seems to differ, since it apparently consists of small tubercles of
nearly equal size. It has been suggested by Holzapfel and Hennig that Lima
pseudocardium, Reuss,’ may be identical with L. granulata, but the ornamentation
on the ribs of that species appears to be unknown.

Remarks.—This species has been referred to Limea by Brauns, Zittel, and
Griepenkerl, but later writers—Holzapfel, Hennig, and Rayn—retain it in the
genus Lima since they find no evidence of the existence of a taxodont hinge.
The specimens which I have seen do not show the hinge.

The outline of the shell varies to some extent in L. granulata, depending mainly
on the obliquity of the valves. The appearance of the ribs varies considerably and
is probably due chiefly to the state of preservation ; in the more perfect specimens
the terminations of the scale-like spimes become erect, in others the spines are
in the form of sloping scales, whilst in some cases they are represented by
tubercles only. The number of ribs also shows variation.

«T/Hist. du Terr. de Craie’ (1888), p. 148, pl. i, figs. 21—24.
‘Paleont. Indica, Cret. Fauna 8. India’ (1871), vol. iii, p. 419, pl. xxx, fig. 8.

3 «Pie Verstein. der béhm. Kreideformat.’ (1846), pt. 2, p. 33, pl. xxxviii, figs. 2, 3; Geinitz,
“Das Elbthalgeb. in Sachsen” (‘ Paleontographica,’ vol. xx, pt. 1, 1872), p. 204, pl. xlii, figs. 14, 15:
see also Brauns (1876), Fritsch (1877, 1883), Michael (1893), Leonhard (1897).

rw

Palxontographbical Society, 1905.

ie MEO IN OG: A. PA

CRETACKOUS LAMELLIBRANCHITA

HNGLAND.

BY

HENRY WOODS, M.A.

UNIVERSITY LECTURER IN PALZOZOOLOGY, CAMBRIDGE,

VOL. Ti. PART. Ef.

Paces 57—96; Puatres VIII—XI.

LONDON:
PRINTED FOR THE PALZONTOGRAPHICAL SOCIETY.

1905.

A
2M
~ |
. ,

PTERIA. 57

This species was figured from the Norwich Chalk by 8S. Woodward (1833) as
Plagiostoma granulosum, but apparently he was unaware that it had been previously
described and figured by Nilsson under the similar name P. granulatum.
Woodward’s figure seems to have been overlooked by later writers.

Distribution.—Actinocamax quadratus zone of East Harnham, Salisbury. .
Belemnitella mucronata zone of Alderbury, Clarendon (near Salisbury), and various
localities near Norwich. Chalk of Trimingham.

Family—PTERIIDA, Meek.
Genus—Prenria, J. A. Scopoli, 1777.
(‘ Introd. Hist. Nat.,’ p. 397.)

Sub-genus—Oxytoma, Meelk, 1864.

(‘Check List Invert. Foss., N. America,’ p. 39; Meek and Hayden, ‘ Paleont. U. Missouri,’ 1864,
Part I, p. 79.)

Preria (Oxyroma) Cornurniana (d’Orbigny), 1846. Plate VIII, figs. 1, 2,3 a, b, 4-7.

1836. Avrcuna macroprTerRaA, F. A. Rimer. Die Verstein. nord-deutsch. Oolith.-
geb., p. 86, pl. iv, fig. 5 (non Avicula
macroptera, Lamarck, 1819).

1841. _ — — Die Verstein. d. nord-deutsch. Kreide-
geb., p. 64.
1846. — Cornvenrana, A.d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 471,
pl. ecelxxxix, figs. 3, 4.
1846. — perctinata, d’Orbigny. Ibid., p. 473, pl. ecexci, figs. 1—3.
1850. — CornveLrana, — Prodr. de Pal., vol. ii, p. 82.
1850. — PECTINATA, — Thid., p. 82.
? 1868. — Cornveuiana, E. Eichwald. Lethea Rossica, vol. ii, p. 508, pl.
xxii, fig. 1.
1869. —- a F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse, ser. 5),
p. 66, pl. chi, figs. 1—4.,,

1877. -- -— G. Béhm. Zeitschr. d. deutsch. geol. Gesellsch., vol.
XXix, p. 237.
? 1883. a = W. Keeping. Foss., etc., Neoc. Upware and Brick-
hill, p. 109, pl. v, fig. 2.
1884. —_ = O. Weerth. Die Fauna des Neocom. im Teutoburg.
Walde (Palwont. Abhandl., vol. ii),
p- 50.

1 Syn. Avicula, Bruguitre, 1791.

D

58 CRETACEOUS LAMELLIBRANCHIA.

1889. AvicuLa InmQuivatvis, G. W. Lamplugh. Quart. Journ. Geol. Soc., vol. xlv,

p- 615.
1895. — Cornveiana, G. Maas. Zeitschr. der deutsch. geol. Gesellsch., vol.
xlvii, p. 267.
1895. - — F. Vogel. Holliindisch. Kreide, p. 55.
1896. —- = A. Wollemann. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xlviii, p. 842.
1900. — -- — Die Biv. u. Gastrop. d. deutsch. u.

hollind. Neocoms (Abhandl. d. k.
preussisch, geol. Land., N. F., pt.
31), p. 52.
1901. Oxyroma INEQUIVALVE var. MACROPTERA, L. Waagen. Jahrb. d. k.-k. geol.
Reichsanst., vol. li, pp. 12,
15, pl. i, figs. 7, 14, 15.

Description.—Shell obliquely oval, rounded. Height a little greater than length.

Left valve moderately convex. Anterior ear triangular. Posterior ear larger
and longer than the anterior. Surface of valve with from 12 to 21 main ribs which
are rounded, and form projections on the margin of the valve. Between the main
ribs are broad flat interspaces in the middle of each of which a smaller rib occurs,
and between these secondary ribs and the main ribs one or more still smaller ribs
are found. On the middle and posterior parts of the valve the ribs are nearly
straight, but on the anterior part they curve forward. Similar ribs occur on the
anterior ear; on the posterior ear much smaller ribs are present, and growth
lines are seen. Fine concentric ridges cross both ribs and imterspaces.

Right valve nearly flat, with many small, sometimes irregular ribs, which may
be alternately large and small. Anterior ear rather small, with a well-marked
byssal sinus. Posterior ear large, pointed, with small radial ribs.

Measurements :

(1) (2) (3)
Length : 26 : 24. : 13 mm.
Height : 27 : 25 : Ss

1, 2) Speeton Clay (D 1), Speeton.
I 2 I
(8) Claxby Ironstone, Claxby.

Affinities —P. (Ovytoma) Cornueliana is distinguished from the other Cretaceous
species of Orytoma by the broad interspaces on which several smaller ribs occur.
It belongs to the persistent and variable series of forms, ranging from the Rheetic
to the Chalk, of which Pteria inequivalvis (Sowerby) is the type, and it is regarded
by L. Waagen as only a variety of that species.

In most of the English specimens the main ribs are more numerous but less
prominent than in the examples figured by d’Orbigny and by Pictet and Campiche.

PTHRIA. 59

But the number of those ribs varies considerably, and our specimens agree per-
fectly with the figures given by Waagen. The specimens from Faringdon are
smaller than those found in the Speeton Clay, and they present some resemblance
to P. pectinata (see below), but the presence of several smaller ribs in the inter-
spaces connects them with P. Coriueliana.

Types—From the Hils-thon of Elligser Brink. The specimen from Upware
figured by Keeping is in the Sedgwick Museum ; it is imperfectly preserved, but is
probably an example of this species.

Distribution.—Speeton Clay (zone of Belemuites lateralis, D1) of Speeton.
Claxby Ironstone (zone of PB. lateralis) of Claxby. Tealby Clay (zone of B.jaculum)
of Claxby. Lower Greensand of Faringdon. Gault of Folkestone.’

Prerta (Oxyroma) rectinata (Sowerby), 1836. Plate VIII, figs. 8a,b, 9, 10a, b,
11-18, 14a, b.

1836. Avicuna pectinata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp.
128, 338, pl. xiv, fig. 3.

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 163.
1869. — -— F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5),
p. 70.
Non 1846. — -- A. d@Orbigny. Pal. Frane. Terr. Crét., vol. i, p. 473,

pl. ceexci, figs. 1—3.

Description.—Shell small, obliquely oval, with evenly rounded margin. Height
a little greater than length.

Left valve convex, ornamented with numerous slender ribs often having sharp
summits. Frequently the ribs are of two sizes—larger and smaller, alternating in
a more or less regular manner. But in some cases the ribs near the margin of the
valve are of equal or nearly equal size. The interspaces are flattened and con-
siderably broader than the ribs. Anterior ear moderately large, triangular, the
outer angle nearly a right angle; surface with ribs similar to those on the rest of
the valve. Posterior ear much longer than the anterior, wing-like, with concave
erowth-lines; on the dorsal part a few slender ribs occur but are often indistinct
or absent near the valve.

Right valve moderately convex dorsally, flattened ventrally, surface smooth or
with very fine radial and concentric ribs. Posterior ear large, not distinctly limited.
Anterior ear small.

1 The only specimen seen from this horizon is in the British Museum, No. L. 16,880.

60 CRETACEOUS LAMELLIBRANCHIA.

Measurements :

(1) (2) (3) (4) (5)
Length ; 16 : 10 : S5D ae 9 - 8mm.
Height’ : 17 : 12 : 10 : 11 : Das

(1) Hythe Beds (Bargate Stone), St. Katherine’s Chapel, Guildford.
(2—5) Folkestone Beds, Folkestone.

Affinities —The shell in this species is smaller than in P. Cornueliana (see
above); also the main ribs on the left valve are closer together, more numerous,
and between them not more than one small rib is found. The ornamentation on
the right valve is very much finer than in P. Cornueliana, See also Pteria
(Oxytoma) tenuicostata (below).

T'ype.—Vhe type came from the Folkestone Beds of Risborough, but appears to
have been lost. Another specimen, however, from the same locality is in the
Fitton Collection in the Museum cf the Geological Society.

Distribution—Hythe Beds (Bargate Stone) of St. Katherme’s Chapel, Guild-
ford. Sandgate Beds of Parham. Folkestone Beds of Folkestone. Recorded by
Topley from the Hythe Beds of Hythe. Gault of Folkestone (British Museum,
No. L, 4926).2 Upper Greensand of Ventnor, and Crook Hill, Cheddington
(Dorset).

Prerta (Oxyroma) sp. Plate VIII, fig. 15a, b.

Some very small examples of a Pteria similar to P. pectinata are found in the
Totternhoe Stone of Hitchin. They are not well preserved, but appear to be dis-
tinguished from P. pectinata by the presence of transverse ribs placed at regular
distances in the spaces between the radial ribs.

Prerta (Oxyroma) puBIA (Htheridge), 1881. Plate VIII, fig. 16a, b.

1881. Avieuna pupa, R. Htheridge. In Penning and Jukes-Browne, Geol. Cam-

bridge, p. 145, pl. ii, figs. 4, 4a.

Remarks.—Vhis is known only by the two type specimens—one being a right
valve separated from the matrix, the other a left showing the interior only. The
surface of the right valve is smooth. Since the exterior of the left valve is un-

1 Measured obliquely to the hinge-line.
2 The species recorded from the Gault of Folkestone as Avicula Rauliniana, dV’ Orbigny (see Jukes-
Browne, ‘ Cretaceous Rocks of Britain,’ vol. i, p. 465), is probably Pteria pectinata.

PTERIA. 61

known, the characters and affinities of this “species” cannot be determined. The
left valve has a length of 6 mm.
Types.—In the Sedgwick Museum, Cambridge.

Distribution.—Totternhoe Stone (zone of Holaster swhglobosus) of Burwell!

Preria (Oxytoma) TEenuicosrata (Rémer), 1841. Plate VIII, figs. 17 a-d, 18,
19/a..b, 20a, 0, 2a, bs 22: 23:

184]. Avicuna tineava, F. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p- 64, pl. viii, fig. 15 (A. tenwicostata on

pl. viii).

1850. — suBiingata, A, d’Orbigny. Prodr. de Pal., vol. ii, p. 249.

1869. — teENuIcosta, F, J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5),
p. 73.

1878. — tENurcostata, J. F. Blake. Proc. Geol. Assoe,, vol. v, p. 259.

1882. — — H. Schrider. Zeitschr. d. deutsch. geol. Gesellsch.,

vol. xxxiv, p. 271.
1888. — — A. Peron. L’Hist. du Terr. de Craie, p. 153, pl. i,
figs. 11, 12.
1904. a — A.W, Rowe. Proc. Geol. Assoc., vol. xviii, p. 266.
Non 1845. — — A. d Orbigny, in Murchison, de Verneuil, and Keyser-

ling. Géol. de la Russie d'Europe,
vol. ii, p. 490, pl. xiii, figs. 5—7.
— 1854. — urneata, J. Morris. Cat. Brit. Foss., ed. 2, p. 163.

Description.—Shell obliquely oval, usually longer than high.

Left valve moderately convex ; with evenly convex margins, except the postero-
dorsal, which is slightly concave. Lars large, the anterior indistinctly limited, and
with its outer angle rectangular or slightly obtuse. Posterior ear longer and more
distinctly limited than the anterior, with the dorsal portion extended and wing-
like.

Ornamentation of left valve consists of numerous (sometimes as many as 100)
narrow, well-marked, evenly rounded ribs separated by broad, flat interspaces.
The anterior ribs are slightly less prominent than the others; those near the pos-
terior border are often closer together. At the margin of the valve the ribs usually

1 Another specimen from the same locality and horizon was described by Etheridge as Avicula
filata (Penning and Jukes-Browne, ‘Geol. Camb.,’ p, 144, pl. ii, fig. 3). I am unable to accept the
generic position assigned to this species by Etheridge; it may be an Ostrea, but appears to be closely
allied to the shell described as Anomia subradiata by Reuss (‘ Die Verstein. der bohm, Kreideformat.,’
pt. 2, 1846, p. 45, pl. xxxi, figs. 18, 19). The type and three other specimens of Avicula filata are in
the Sedgwick Museum, Cambridge.

62 CRETACEOUS LAMELLIBRANCHIA.

show a more or less regular alternation in size, but sometimes two or three of the
larger ribs occur in proximity without the intervention of smaller ribs. In some
cases between the large and small ribs a rib of still smaller size is found. Some of
the large ribs start from near the umbo; others start at some little distance from
it but soon reach the same size as the primary ribs; still other ribs are intercalated
at a greater distance from the umbo and do not attain the same size as the
earlier ribs. The anterior and posterior ribs have a shght curvature; the others
are more nearly straight. Occasionally the anterior and posterior ribs have a
faintly marked nodose appearance. The interspaces are smooth, or haye a very
faintly marked radial ribbing. ‘The anterior ear is ornamented with ribs similar to
those on the remainder of the valve, but they are of uniform or nearly uniform
size. The posterior ear is marked with growth-lines parallel to its posterior con-
cave border ; radial ribs also occur, and are rather larger and more widely separated
on the dorsal portion than on the part near the junction with the rest of the valve.

Right valve much smaller than the left; flattened, but convex in the median
dorsal part. Anterior ear with a deep sinus. Posterior ear much larger, but not
marked off from the rest of the valve. Surface smooth, or with very faint concen-

tric lines.
Measurements of left valves :
(1) (2) (3) (4) (5) (6) (7) (8)
Length ; 27 26 6 2075 19 19 3P 12 mm.

Dy 13*5
Height (oblique) 25°5 23 2 19 18 7, ea iomeleleo ore

(1, 8) A. quadratus zone, West Harnham.

(2, 5) 9 , Coddenham.
(4) Upper Chalk, Ruston Parva.
(3, 6, 7) ” Wells.

Affinities —Pteria danica (Ravn)! is similar in outline and the general
character of its ornamentation to Pteria tenuicostata, but appears to be dis-
tinguished by the possession of fewer ribs and by their absence in the neighbour-
hood of the umbo.

In the character of its ornamentation P. tenwicostata closely resembles P.
pectinata (see p. 59), but is distinguished by its larger size, relatively greater
length, and smaller convexity; also the ribs are more numerous, the ears are
relatively larger, and the anterior left ear is less distinctly limited.

The specimen from Simbirsk figured by d’Orbigny (1845) as Avieula tenwi-
costata differs from that species in the possession of fewer and stronger ribs. — It
was subsequently regarded by d’Orbigny’ as an example of Avicula laripes, Morton.’

1«Mollusk. i. Danmarks Kridtaflej,’ i. (1902), p. 79, pl. i, figs. 1, 2.
2«Prodr. de Pal.,’ vol. 11 (1850), p. 249.
8 « Synopsis Org. Remains Cret., U.S.’ (1834), p. 63, pl. xvii, fig. 5.

PTERIA. 63

Remarks.—In England this species has, up to the present time, been definitely
recognised in the Actinocamax quadratus zone only.

The specimen figured by Rémer is relatively higher than most of the English
examples, but in other characters there is close agreement.

Pteria seminuda (Dames)* resembles Pteria tenuicostata, but appears to differ
in the ribs on the left valve being of more nearly uniform size, and in the presence
of distinct ornamentation on the right valve.

T'ype.—The type is stated by Rémer to have come from the Lower Chalk of
Lindner Berg, near Hanover, but according to Dr. J. Bohm the horizon is really
the quadratus Chalk.

Distribution.—Zone of Actinocamaxr quadratus of West Harnham, near Salisbury,
and Sewerby (Yorkshire). Upper Chalk (? A. quadratus zone) of Coddenham
(Suffolk), Wells (Norfolk), and Ruston Parva (Yorkshire).

Sub-genus—Psevvorrera, fF’. B. Meek, 1873.

(‘6th Ann. Rep. U.S. Geol. Survey of the Territories,’ p. 489; Meek, ‘Invert. Cret. and Tert. Foss.
U. Missouri’ (Rep. U.S. Geol. Survey, vol. ix, 1876), p. 29.)

Prerta (PseuporPTERA) sUBDEPRESSA (d’Orbigny), 1850. Plate IX, fig. la, b.

1845. AvicuLa pepressa, H. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 247, pl. 1,
fig. 7 (non A. depressa, Miinster, 1841).

1850. — suBpEPREsSA, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 119.

1854. — pepRESSA, J. Morris. Cat. Brit. Foss., ed. 2, p. 163.

1855. -— SUBDEPRESSA, G. Cotteau. Moll. Foss. de l’Yonne, p. 104.

1869. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Mat¢r. Pal. Suisse, ser. 5),
p. 70.

1871. — — F. Stoliczka. Paleeont. Indica, Cret. Fauna 8. India,

vol. iii, p. 898.

Remarks.—This species is very imperfectly known at present. It resembles
P. haldonensis from the Upper Greensand of Haldon (see below) but is easily dis-
tinguished by the strong concentric ridges; it also appears to be relatively longer
and less convex.

Type.—In the Museum of the Geological Society (No. 2050).

Distribution —Lower Greensand (Crackers) of Atherfield. Recorded by Topley
from the Atherfield Clay of Peasmarsh and Shalford.

1 « Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. xxvi (1874), p. 765, pl. xxi, fig. 3; Notling, ‘ Die Fauna
d. baltisch. Cenoman.’ (Paleont. Abhandl., vol. ii, 1885), p. 21, pl. iii, figs. 7, 8.

64 CRETACEOUS LAMELLIBRANCHIA.

Prerta (PsrvporTEra) anomata (Sowerby), 1836, Plate IX, figs. 2a—-d, 3a, b, 4a, b.

1836. Avicuna anomata, J. de C. Sowerby. ‘Trans. Geol. Soc., ser. 2, vol. iv, pp.
240, 342, pl. xvii, fig. 18.

F 1846. = — A. E. Reuss. Die Verstein. der bohm. Kreideformat.,
pt. 2, p. 22, pl. xxxii, figs. 1—3.
? 1842. Gervr“iia — H.B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 3, p. 80, pl. xx, fig. 38.
? 1845-6. AvicvuLa — — Grundriss d. Verstein., p. 459, pl. xx,
fig. 5.
? 1850, — = — Das Quadersandst. oder Kreidegeb. in
Deutschland, p. 170 (partim).
1854, — J. Morris. Cat. Brit. Foss., ed. 2, p. 163.
1868. — — A. Briart and F. L. Cornet. Descript. Mineralog. Géol.

et Pal. de la Meule de Bracquegnies (Mém.
cour. et Mém. des Say. ¢trangers, vol. xxxiv),
p. 52, pl. iv, fig. 7.

1869. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser.
5), p. 71.
1871. — — FF. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. iii, p. 398.
? 1873. — — H.B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto-

graphica, vol. xx, pt. 1), p. 207, pl.
xlvi, figs. 5, 6.
1893. — — R. Michael. Zeitschr. der deutsch, geol. Gesellsch., vol.
xlv, p. 233.

Non 1846. =. — A. dOrbigny. Pal. Franc. Terr. Crét., vol. ii, p. 478, pl.
eeexei, figs. 1—3.
— 1850. “+ — dd Orbigny. Prodr. de Pal., vol. ii, p. 167.
? — 1877. — — A. Fritsch. Stud. im Gebiete der béhmn. Kreideformat. :

II, Weissenberg. u. Malnitz. Schicht., p.
128, fig. 108.
— 1883. — — — Thid., ITI, Iserschicht., p. 109.

Description.—Shell rather large; outline (without the ears) triangular, very
oblique ; anterior margin convex, forming a rounded angle with the sinuous postero-
ventral margin. Umbo of left valve pointed, acute, near the anterior extremity.
Apical angle about 45°.

Left valve very convex, with a strong, rounded ridge extending from the
umbo to the postero-ventral extremity. In front of this ridge the shell curves
rapidly downwards, and becomes nearly vertical to the plane of the valves near
the anterior margin and near the anterior ear. Behind the ridge the valve is
flattened and slopes dorsally (fig. 2.7); but this part is sometimes divided into two

PTERIA. 65

by a median step-like fold (fig. 3.@). A narrow part adjoining the posterior ear
slopes rather rapidly.

Anterior ear of moderate size, convex, much higher than long. Posterior ear
large, united to the whole of the postero-dorsal margin of the valve; posterior
margin of ear slightly concave or sinuous, forming an obtuse angle with the hinge-
line and also with the postero-ventral margin.

Ornamentation consists of numerous radial ribs which are straight or slightly
undulating, and extend over the larger part of the valve. On the posterior ear the
ribs are narrow and separated by broad, flat or slightly concave interspaces. On
the flattened part of the valve the ribs are rather more rounded and become less
distinct towards the postero-ventral margin in large specimens. In front of the
main ridge the ribs are closer together and the interspaces very narrow; on the
anterior part of the valve and on the anterior ear, ribs are either absent or
indistinct. Numerous, close-set, regular, concentric linear ridges cross both ribs
and interspaces.

In small specimens (figs. 4, ) haying the ornamentation well preserved, the
ribs on the flattened part of the valve are narrow, rounded, distinctly limited,
and separated by broad imterspaces; new ribs are introduced in the middle of
some of the interspaces. The ribs and interspaces are crossed at regular intervals
by concentric ridges which form squares or oblongs with the ribs. On the posterior
ear similar ornamentation occurs, but the concentric ridges cut the ribs obliquely.

Right valve not seen.

Measureincits :

(1) (2)
Umbo to postero-ventral extremity 86 : : 75 mm.
Length of hinge-line —. 49 ay. ier

(1, 2) Blackdown.

Affinities —The specimen from the Cenomanian of Le Mans figured by
d’Orbigny as Avicula anomala appears to be distinct from Sowerby’s species on
account of its larger apical angle and its fewer, stronger, and more spiny ribs. See
also P. (Pseudoptera) haldonensis (below).

The character of the hinge in this and the other species here included in the
sub-genus Pseudoptera is unknown ; consequently their systematic position cannot
be regarded as definitely determined.

Remarks.—The only examples which I have seen are the type specimen, six
specimens in the British Museum, and two in the Museum of Practical Geology.
Those from Haldon have the ornamentation very perfectly preserved.

T'ype.—In the Bristol Museum, from Blackdown.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown
and Haldon.

66 CRETACEOUS LAMELLIBRANCHIA.

Prpria (PSEUDOPTERA) HALDONENSIS, sp. nov. Plate IX, figs. 5, 60,6, 7,8 a-—c, 9, 10.

Description —Shell of moderate size, triangular, very oblique. Anterior margin
slightly convex, forming a rounded angle with the postero-ventral margin. _Umbo
pointed, acute, near the anterior extremity. Apical angle about 43°.

Left valve very convex, with a sharp carina extending from the umbo to the
postero-ventral angle. The part of the valve in front of the carina is bent
sharply downwards along its whole length, and is ornamented with from ten
to eighteen slender, linear ribs, which are separated by broad flat interspaces.
The number of ribs increases with age owing to the intercalation of new ribs
in the interspaces. The space between the carina and the first mb, and
sometimes also between the first and second rib, is greater than the space
between the ribs near the middle of the anterior part of the valve. Minute
spiny projections are present on the ribs in well-preserved specimens. A similar
but rather stronger rib, also with spiny projections, occurs on the carina.
Behind the carina two short ribs, extending from near the middle to the margin of
the valve, are sometimes seen. The larger part of the valve behind the carina is
flattened and smooth except for numerous, shghtly curving growth-ridges, which
are continued on to the posterior ear, and are sometimes seen in front of the carma,
where they may become more prominent.

Anterior ear small, with rounded margin, indistinctly separated from the
remainder of the valve, ornamented with radial ribs similar to those on the
adjoining part of the valve.

Posterior ear compressed, very large, separated from the remainder of the
ralve by a very shallow depression. Growth-ridges concave and parallel with
the posterior margin.

Right valve not seen.

Measurements :

(1) (2 (3) (4) (5)
Height (oblique) . 28 . 26 . 25 . 23 . 18mm.
Length of hinge-lne’19 . 16 . 18 Loy. gral vie

(1—5) Upper Greensand, Haldon.

Affinities. —This species is closely allied to Pteria (Pseudoptera) varicosta (Reuss),”
from the Gosau Beds of St. Wolfgang (Salzburg), but is distinguished by the
smaller obliquity of the shell, by the angle formed by the anterior and postero-

1 This measurement is approximate only, since the posterior wing is usually imperfectly preserved.

> Reuss, ‘Char. d. Kreideschicht. in den Ostalpen,’ ete. (Denkschr. d. k. Akad. Wissensch. Wien,
Math.-nat. Cl., vol. vii, 1854), p. 147, pl. xxviii, tig. 16; K. A. Zittel, ‘Die Bivalven d. Gosaugeb.’
(Ibid., vol. xxv, pt. ii, 1866), p. 90, pl. xiii, fig. 6; A. glabra, Geinitz, ‘Das Elbthalgeb. in Sachsen’
(Paleontographica, vol. xx, pt. i, 1873), p. 208, pl. xlvi, fig. 7, and pt. ii, pl. xi, fig. 2°; Ndétling, ‘ Die
Fauna d. baltisch. Cenoman.’ (Paleont. Abhandl., vol. ii, 1885), p. 22, pl. iii, fig. 9.

PTERIA. 6

NI

ventral margins being smaller, and by the shorter postero-ventral margin. It also
resembles P. (Pseudoptera) ignabergensis (Lundgren),'! from the Senonian of
Ignaberga.

P. (Pseudoptera) haldonensis is distinguished from the young of P. (Pseudoptera)
anomala (see above) by its sharp carina; by the part of the valve behind the carina,
and the posterior wing, beg smooth; also by the strong and more widely sepa-
rated ribs in front of the carina.

Types.—In the British Museum and the Sedgwick Museum.

Distribution —Upper Greensand (zone of Pecten asper) of Haldon.

Prerta (PSEUDOPTERA) GAULTINA, sp. noy. Plate IX, figs. 11a, b, 12 a,b.

Description.—Shell small, very oblique. Umbo acute, near the anterior
extremity. Apical angle 26° to 32°.

Left valve moderately convex, with the median triangular part raised but
flattened ; in front of this the valve bends sharply to the anterior margin ; behind,
it bends rather sharply to join the posterior ear, which is distinctly demarcated.
Anterior ear small. Posterior ear moderately large, united to the greater part of
the postero-dorsal margin of the valve ; its posterior margin concave.

A few narrow, well-defined radial ribs occur on the anterior part of the raised
triangular portion and just in front of it. In some cases less distinct ribs with
spiny projections are present on the whole of the triangular part of the valve.
Growth-ridges are often well-marked, and are continued on to the posterior ear.

Measurements :

Hinge-line. : : : Liam:
Height (oblique) : é Sess gs

Black Ven.

Affinities —This species is distinguished from Pteria (Pseudoptera) haldonensis
(see above) by (1) the greater obliquity of the shell, (2) the smaller apical angle,
(3) the absence of the sharp carina, (4) the distinctly limited posterior ear.

Types.—In the Museum of Practical Geology (No. 10,780) and the Sedgwick
Museum.
Distribution.—Gault of Black Ven.

Prerta (Pseuporrera) c@ruLescens (Nilsson), 1827. Plate IX, figs. 13-16, 17,4,
18, 19 a,b.
1827. Avicuna cervLescens, S. Nilsson. Petrif. Suecana, p. 18, pl. iu, fig. 19.
? 1836. -- A. Goldfuss. Petref. Germ., vol. ii, p. 132, pl. exviii,
fig. 6. .

1* Mollusk. i Mammilatus och Mucronata Zonerna i Nordéstra Skane’ (1894), p. 44, pl. i, fig. 2.

68 CRETACEOUS LAMELLIBRANCHIA.

? 1841. AvicuLa ceruLescens, fF. A. Riimer. Die Verstein. d. nord-deutsch. Kreide-
geb., p. 64.

1850. — -— A, d'Orbigny. Prodr. de Pal., vol. ii, p. 249.
1888. — cmruLEscEeNs A. Peron. Hist. Terr. de Craie, p. 155, pl. i, fig. 14.
? 1889. — c@ruuescens FL. Holzapfel. Die Mollusk. Aachen. Kreide (Pale-
ontographica, vol. xxxv), p. 227.
1897. _ — A, Hennig. Revis. Lamell. i Nilsson’s ‘ Petrif.

Suecana,’ p. 54, pl. iu, figs. 25—27.

Description._Shell rather small, oblique, triangular. Anterior margin slightly
convex or nearly straight. Umbo rather near the anterior extremity, sometimes
curved slightly backwards. Anterior ear small, not distinctly marked off from the
rest of the valve. Posterior ear large, triangular, its inner margin not limited, its
posterior margin slightly concave and continuous with the postero-ventral margin
of the valve. Median part of the valve raised, extending obliquely backwards, some-
times subcarinate anteriorly. In front of this raised part the valve is bent more or
less sharply; behind, it is compressed gradually. Surface with weak radial ribs, which
are straight or slightly undulating, and bear small spiny or scaly projections some-
times close together, sometimes more or less widely separated. The ribs may
occur on the anterior part only, or may be present over the entire shell, including
the ears. Often on the anterior part they are closer together than elsewhere. The
number of ribs and the width of the flat interspaces vary in different specimens.
New ribs may be introduced in the interspaces at varying distances from the umbo.
In some specimens numerous fine concentric lines are seen.

Measurements :

(1) (2) (3)
Length . é 1 | : 11 5 10° mm.
Height. ; 13 é 12 ; 10°5
(1) A. quadratus zone, East Harnham.

(2) B. mucronata zone, Norwich.
(3) x , Clarendon.

39

Affinities —The imperfect specimen from the Lower Senonian of Brunswick
figured by G. Miller’ as Avicula sp. may perhaps be an example of P. cwrulescens.

Avicula glabra, Reuss,? resembles in form P. cwrulescens, but is distinguished
by the absence of radial ribs.

Avicula subnodosa, Hagenow,’ from the Senonian of Riigen, is perhaps iden-
tical with P. caerulescens, but im the absence of a figure of the former I am unable
to make a comparison.

1 «Mollusk. d. Untersen, v. Braunschweig u. Ilsede’ (1898), p. 39, pl. v, fig. 10.
2 «Die Verstein. der bohm. Kreideformat.’ (1846), pt. 2, p. 22, pl. xxxii, figs. 4, 5.

* «Neues Jahrb. fiir Min.,’ ete. (1842), p. 559.

AUCELLA. 69

Remarks.—The English specimens have the median part of the valve apparently
less sharply marked off from the anterior and posterior parts than it is in the
examples figured by Hennig, but they agree in this respect with the figure given
by Peron.

The specimens show some variation in obliquity and in their relative height
and length. The differences seen in the ornamentation are probably due, in part,
at any rate, to imperfections in the preservation of the surface layer of the shell.
Like Peron, I have seen no specimen of the right valve.

Examples of this species are preserved in the Norwich Museum, in Dr. Black-
more’s collection, and in Mr. Brydone’s collection.

Distribution —Zone of <Actinocamax quadratus of East and West Harnham
(Salisbury). Zone of Belemnitella mucronata of Clarendon (Salisbury) and Norwich.
Chalk of Trimingham.

Genus—AvcELLaA, A. Keyserling, 1846.

(‘ Reise in das Petschora-Land,’ p. 297.)
AUCELLA VOLGENSIS, Lahusen, 1888. Plate X, figs. 1 a—-c, 2 a-c.
) ’ Db

1888. AvucrLua voneensis, J. Lahusen. Ueber die russischen Aucellen (Mém. du
Comité géol. Russ., vol. viii, No. 1), p.

38, pl. iii, figs. 1—17.

1896. -- — A. P. Pavlow. Quart. Journ. Geol. Soc., vol. lii, p. 549,
pl. xxvii, fig. 1.
1896. _ — var. RADIOLATA, Pavlow. Ibid., p. 550, pl. xxvii, fig. 2.

Description.—Shell large, obliquely ovate, much higher than long, moderately
inflated, with regularly curving margin.

Right valve of moderate convexity, flattened. Umbo relatively small, and
curving only slightly. Anterior ear triangular, with a deep, narrow byssal sinus.
Posterior ear indistinctly limited.

Left valve very convex and rounded, the dorsal portion continued into a large
and prominent umbo which curves anteriorly. Postero-vyentral part of valve pro-
duced and somewhat compressed.

Surface of valves with concentric growth-ridges, sometimes produced into
lamelle, and forming regular curves.

Measurements :

Q) (2)
Length , : : ; 45 ; : 36 mm.
Height of left valve (oblique) 66 : : 19) as
Thickness (both valves) ; 32 ; : DAs ie

(1, 2) Spilsby Sandstone, Donnington.

70 CRETACEOUS LAMELLIBRANCHIA.

Affinities —The shell in this species is larger, relatively higher, more oblique,
and less inflated than in A. Keyserlingiana (see below). The right valve is more
flattened, and its umbo is only slightly curved. The umbo of the left valve is
larger and more prominent.

Remarks.—The only specimens I have seen are internal casts from the Spilsby
Sandstone. The example of this species described by Pavlow as var. radiolata
shows faint radial ribs on the internal cast of the right valve, and a slight
depression on the left valve extending from the umbo to the postero-ventral
margin (Plate X, fig. 2).

Types.—From the Upper Volga beds of Kaschpur (Simbirsk), Staraja-Rjasan,
and Olenek. The specimens figured by Pavlow are in the Sedgwick Museum and
are here re-figured.

Distvibution.—Spilsby Sandstone (zone of Belemiites lateralis) of Donnington.

AvcetLa Keryseritinciana, Trautschold, 1868. Plate X, figs. 3a—d, 4a, b, 5.

1837. Inocrramus concentricts, G. Fischer de Waldheim. Oryctographie du
gouvernm. de Moscou, p. 177,
pl. xx, figs. 1—3.
1846. AucELLA CONCENTRICA, var. RUGOSA, A. Keyserling. Reise in das Petschora-
Land, p. 300, pl. xvi, fig. 16.
1850. AvicuLa (Bucura) n. sp., F. Rimer. Neues Jahrb. fiir Min., ete., p. 393.
1868. Avcrenta Keysertinerana, H. Trautschold. Verhandl. d. russisch-kaiser-
lich. mineral. Gesellsch. in Peters-
burg, ser. 2, vol. ili, p. 250.
1874. -- CONCENTRICA, var. RUGOSA, F. Toula. Mesozoisch. Verstein. v. d.
Kuhn-Insel (Die zweite deutsch.
Nordpolf., in 1869, 1870, unter
Kapitiin K. Koldewey), vol. ii,
p- 503, pl. ii, figs. 2, 3.
1874. = = var, RuGosIssImaA, F. Toula. Ibid., p. 504, pl. ii,
fig. 4.
1875. Perna mmsricatus { Bean MS.], J. Phillips, Geol. Yorks., pt. i, ed. 3, p. 247.
_- — venustutus [| Bean MS.], Phillips. Ibid., p. 247.
1884. AvicuLa? reuTospuRGiENsis, O. Weerth. Neocom. im Teutoburg. Walde
(Paleont. Abhandl., vol. ii),
p. 50, pl. ix, fig. 9.
1886. Avcrnna Krysertrnaiana, J. Lahusen. Mém. Acad. Imp. St. Pétersbourg,
ser. vii, vol. xxxiii, No. 7, p. 4.
1888. — Keyseruinat, J. Lahusen. Ueber die russischen Aucellen (Mém.
Comité géol. Russ., vol. vii, No. 1),
pp: 21, 40, pl. iv, figs. 18—23.
1889. InocERAMUS VENUSTULUS ef ImBRIcATUS, G. W. Lamplugh. Quart. Journ.
Geol. Soc., vol. xlv, p. 615.

AUCELLA. 71

1896. AucreLia Keyseruines, A. P. Pavlow. Ibid., vol. lii, p- 550, pl. xxvii, fig. 3.

1899. — — G. Maas. Zeitschr. d. deutsch. geol. Gesellsch., vol.
li, p. 249.
1900. — = A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.

hollind. Neocoms (Abhandl. d.
k. preussisch. geol. Land., N. F.,
pt. 31), p. 56, pl. ii, figs. 6—9.
1901. = — J. F. Pompeckj. Neues Jahrb. fiir Min., ete., Beil.-
Bd. xiv, p. 319, pl. xv, figs. 3, 6,
8—10, 13, 14, 17, 18, 20, 21.
1903. — — A. Wollemann. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. lv, p. 34 (Briefl. Mitteil.).

Description.—Shell of moderate size, oblique, with more or less triangular out-
line and rounded margins, higher than long, inflated. Umbones prominent, at the
anterior end of the hinge-line, almost touching, curved inwards and forwards.

Right valve convex in the neighbourhood of the umbo, but usually flattened
elsewhere. Anterior ear close to the umbones, triangular, convex, narrow where
united to the rest of the valve, with a deep and narrow byssal sinus. Posterior
ear longer, but indistinctly limited.

Left valve much more convex than the right valve, especially in the dorsal part,
somewhat compressed posteriorly; greatest convexity between the umbo and the
postero-ventral extremity. Umbo more prominent than in the right valve. Ears
indistinctly limited.

Both valves ornamented with many narrow, concentric lamelle which are
placed more or less vertically to the surface and are separated by broad, flat
interspaces. The lamelle occur at fairly regular intervals, but the distance
between them varies on different parts of the shell. They curve gently on the
median part of the valve, but bend more sharply in passing on to the anterior
and posterior parts, where they become closer to one another. The lamelle
have often disappeared from the parts near the umbones.

Measurements :

@) (2) (3) (4)
Length . F 31 : 28 : 24 ; 18 mm.
Height . 2 39 : 32 : 30 : One i
Thickness. — : 16 16 ; ire

(1—4) Claxby Ironstone, Claxby.
Affinities —See Aucella volgensis (p. 69).
Type.—tThe specimens figured by Pavlow are in the Sedgwick Museum.
Distribution.—Claxby Ironstone (zone of Belemnites lateralis) of Claxby.
Speeton Clay (zone of Beleimnites jaculwm) of Speeton.

CRETACEOUS LAMELLIBRANCHIA.

Genus—Avcrtiina, J. F. Pompechkj, 1901.

(‘Neues Jahrb. fiir Min.,’ etc., Beil.-Bd. xiv, p. 365.)

AUCELLINA GRYPHmOIDES (Sowerby), 1836. Plate X, figs. 6a—d, 7a—c, 8a, b,

1836.

1841.

1846.

1850.
1853.

1854.
1856.

1864.

1869.

1875.

1882.

1893.

1895.

1899.

1901.

1902.

Non 1829.

? Non 1847.

9a—c, 10—13.

AvicuLa arypHmorpEs, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv.
pp- 156, 335, pl. xi, fig. 3.

— — F. A. Romer. Die Verstein. d. nord - deutsch.
Kreidegeb., p. 64, pl. viii, fig. 16.
Inoceramus Coquanpianus, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii,
p- 505, pl. ececiii, figs. 6—8.

— — -— Prodr. de Pal., vol. ii, p. 139.
AUCELLA GRYPHROIDES, A. v. Strombeck. Zeitschr. der deutsch. geol.

Gesellsch., vol. vy, p. 509.
J. Morris. Cat. Brit. Foss., ed. 2, p. 163.

AUCELLA - A. v. Strombeck. Zeitschr. der deutsch. geol.
Gesellsch., vol. viii, p. 488.

—- — H. Bilsche. Neues Jahrb. fiir Min., ete., p. 669.
Inoceramus Coquanpiants, F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal. Suisse,
ser. 5), p. 111, pl. elx, figs. 9, 10.
AvicuLA GRYPHmOIDES, A. J. Jules-Browne. Quart. Journ. Geol. Soc., vol.

XXxi, p. 298.

AVICULA

— = R. Windmiller. Jahrb. d. k. preussisch. geol.
Landesanst. fiir 1881, pp. 20, 21.
A. v. Strombeck. Zeitschr. der deutsch. geol.
Gesellsch., vol. xlv, pp. 490, 493.
= E. Tiessen. Zeitschr. der deutsch. geol. Gesellsch.,
vol. xlvii, p. 478.
Avcretita Coguanni, D. J. Anthula. Wreidefoss. des Kaukasus (Beitr. z.
Paliiont. u. Geol. Osterr.-Ungarns u.
d. Orients, vol. xii), p. 78.
AUCELLINA GrypHmoIDES, J. FP. Pompeckj. Neues Jahrb. fiir Min., etc.,
Beil.-Bd. xiv, pp. 354, 365,
pl. xvi, figs. 6—8.
_ — A. Wollemann. Limeburg. Kreide (Abhandl. d.
k. preussisch. geol. Landesanst., N. F.,
Heft 37), p. 64, pl. iii, figs. 2, 3.

AVICULA J. de C. Sowerby. Trans. Geol. Soe., ser. 2, vol.
iii, p. 119 | Pseudomonotis
speluncaria (Schlotheim) }.

— — J. Miiller. Petref. der Aachen. Kreidef., pt. 1,
p. 29.

AUCELLINA.

a |
eo

Description.—Shell oval, very oblique, very inequivalve ; dorsal part of posterior
margin more or less straightened, the remaining margins forming a regular curve.

Right valve flattened, but convex near the umbo; height and length nearly
equal. Umbo small, near the middle of the hinge-line, curving slightly. Hinge-
area obtusely triangular. Anterior ear long, triangular, with a very deep, narrow,
curved byssal sinus on each edge of which is a row of tubercles. Posterior ear
usually of about the same length as the anterior ear, but indistinctly limited, with
the outer angle obtuse.

Left valve convex, especially the dorsal part, more compressed postero-ven-
trally, sometimes with a shallow sulcus extending from the umbo to the postero-
ventral extremity. Dorsal portion of the valve produced into a large, prominent,
much curved umbo. Hinge-area obtusely triangular. Posterior ear larger than
the anterior, with a rounded depression between it and the umbo; anterior ear
short, triangular.

Ornamentation consists of numerous concentric growth-lines which sometimes
become lamellar, and are separated by flat interspaces. Small, close-set, radial
ribs occur, especially in the neighbourhood of the umbo.

Measurements of left valve :

(1) (2) (3) (4)
Length . 3 22 : 21 : 18 : 14 mm.
Height (oblique) 29 27 ; 25 ieee

(1I—4) Cambridge Greensand.

Affinities The probable relationship of this species to Awcella has been
pointed out by von Strombeck, Stoliczka, and Jukes-Browne. Recently its
affinities to Pseudomonotis and Aucella have been fully discussed by Prof.
Pompeckj, by whom the genus Aucellina has been established to include Avicula
aptiensis, d’Orbigny, and Avicula gryphxoides, Sowerby. Aucellina is very closely
allied to Aucella, but differs from it in the absence of an articulating groove in
the hinge-area of the left valve.

Tnoceramus Coquandianus, dV Orbigny, was regarded by Jukes-Browne as identical
with Aucellina grypheoides, and I agree with that view. The identity is also sup-
ported by the fact that Pictet and Campiche referred the specimens found in the
Cambridge Greensand to Inoceramus Coquandianus.

Types—1 have not seen the types; Fitton stated that they were in the
collection of Mrs. Murchison, and came from the Upper Greensand of Nursted
and Cambridgeshire (? Cambridge Greensand).

Distribution —Upper Gault of Folkestone and Eastbourne. Red Limestone of
Hunstanton and Speeton. Cambridge Greensand (derived).

Upper Greensand (zone of Sehlaenbachia rostrata) of Hampshire, Devizes, and
near Didcot ; (zone of Pecten usper) of Okeford Fitzpaine and Warminster. Cam-

10

CRETACEOUS LAMELLIBRANCHIA.

i |
=_

bridge Greensand (indigenous). Chloritie Marl of Maiden Bradley, Devizes,
Isle of Wight, Urchfont (Wilts), Holybourne (Hants), and Eastbourne. Chalk
Marl (zone of Schlanbachia varians) of the Isle of Wight, Folkestone, Hunstanton,
Lincolnshire, and Yorkshire. Totternhoe Stone of Fulbourn and Burwell. Zone
of Holaster subglobosus (above Totternhoe Stone) of Eversden (Cambs.).

Family—PERNIDAS, Zittel.

Genus—Gurvitiia, M. J. L. Defrance, 1820.
(‘ Dict. Sci. nat.,’ vol. xviii, p. 502.)

GERVILLIA suBLANCHEOLATA (d’Orbigny), 1850. Plate X, figs. 14—16; Plate XI,
fig. 1. Text figures 7, 8.

1826. Gervi_ira avicuLorpEs, J. de C. Sowerby. Min. Conch., vol. vi, p. 16, pl.
dxi, figs. 1, 2, 3, 5 (not 4), [non Perna
aviculoides, Sowerby, 1814].
1845. — — Hi. Forbes. Quart. Journ. Geol. Soe., vol. i, p. 246.
— AVICULA LANCEOLATA, —— Tbid., p. 247, pl. iu, fig. 8.
50. — SUBLANCEOLATA, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 119.
1853. Gervinra auprina, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de
Genétve, p. 496, pl. xli, fig. 3.
1854. Gerrvitiia anceps, J. Morris. Cat. Brit. Foss., ed. ii, p. 167.
AvicuLA LANCEOLATA, Morris. Ibid., p. 163.
1858. Gervitia anceps, I’. J. Pictet and E. Renevier. Foss. Terr. Aptien (Matér.
Pal. Suisse, ser.1), p. 121,

pl. xvii.
1865. H. Coquand. Mon, Aptien de Espagne, p. 145.
1869. - Aupina, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix

(Matér. Pal. Suisse, ser. 5),
p. 88, pl. clv, figs. 2—4.
1902. Gprvitiera anceps, F’. Frech. Centralb. fiir Min., etc., p. 612 (text-figure).

Description.—Shell elongate, very oblique, slightly inequivalve, the left valve
rather more convex than the right. Posterior extremity lanceolate, but rounded.
Postero-dorsal margin slightly sinuous. Antero-ventral marginal parts nearly per-
pendicular to the plane between the valves and slightly concave. Umbones incon-
spicuous, almost terminal. Only a very small portion of the valve is seen in front
of each umbo; on the left valve this portion is bounded by a linear depression, but
on the right valve it is not limited. The median part of each valve is convex, but
becomes compressed towards the posterior extremity. Between the convex portion
and the hinge-line (posterior to the umbo) is a long, triangular, compressed, wing-
like portion, of which the inner boundary is not limited, and the posterior margin

GERVILLIA. 75

is slightly convex or sometimes almost straight; on this part the growth-lines are
convex posteriorly and curve towards the umbo, except in young specimens where
they curve posteriorly as they approach the hinge-line.

Hinge-line long, forming rather less than half the greatest leneth of the valve,

Fia. 7.—Gervillia sublanceolata (d’Orbigny.) Lower Greensand (Crackers), Atherfield. Sedgwick Museum.
x #. a, left valve; b, antero-dorsal view of another specimen; ¢, left valve of another specimen.

and making an obtuse angle with the posterior margin. Ligament pits large,
usually from six to nine in number, placed at nearly equal distances, and usually of
nearly equal size, except the anterior and posterior, which may be smaller than the
others.

Surface of valves ornamented with growth-lamell only.

76 CRETACEOUS LAMELLIBRANCHIA.

Measurements :
(1) (2) (3) (4) (5) (6) (7) (8) (9)
Hinge-line . ; : . 92 86 86 838 74 66 41 54 41mm.
Umbo to posterior extremity 182 200 182 163 152 149 89 110 86
(1—7) Crackers, Atherfield.
(8, 9) Greensand, Blackdown.

bP)

Affinities.—Gervillia sublanceolata is closely allied to G. anceps, Deshayes,' of
which the types are from the Neocomian of Aube. The English specimens have
usually been referred to the latter species, but Pictet and Campiche regarded them
as distinct.

The characters which separate the two species are (1) the antero-ventral margin
is concave in G. sublanceolata, whereas in G. anceps it is slightly convex or almost
straight; (2) the posterior margin of the posterior wing-hke part is convex, or in
some cases nearly straight, and the growth-lmes on this part of the shell are convex,
whilst in G. anceps the corresponding margin and growth-lines are concave, and the

wing-like part is more distinct; (3) the line of greatest convexity—extending from
the umbo posteriorly—is near the middle of the valve in G. sublanceolata, but near
the antero-ventral margin in G. anceps ; (4) it is possible that G. sublanceolata is less
inequivalve than G. anceps,” but at present this pomt cannot be proved, since only
a few specimens of the latter species showing both valves have been found. All the
examples known of G. anceps appear to be larger and to have thicker shells than
Gt. sublanceolata.

Pietet and Campiche thought that G. anceps could be distinguished by the second
and third ligament pits being close together, whereas im G. sublanceolata the pits
are nearly equidistant. An examination of specimens of the former shows that the
position of the second and third pits, shown m d’Orbigny’s figure, is an individual
variation,’ and is not usually found. Pictet and Campiche mention as another
distinction the sharp line of separation between the posterior wing and the rest of
the valve in G. anceps; although this feature is shown in d’Orbigny’s figure it is not
evident in the specimens.

G. sublanceolata differs from G. cosnenis, de Loriol,‘ in the rapid tapering of
the shell towards the posterior extremity and in the less extensive development of
the posterior wing-like part.

Remarks.—Examples of this species from Atherfield were described and figured
as Gervillia alpina, Pictet and Roux, by Pictet and Renevier and by Pictet and

1 *Mém Soe. géol. de France,’ vol. v (1842), p. 9, pl. x, fig. 3; D’Orbigny, ‘Terr. Crét.,’ vol. iii
(1846), p. 482, pl. ecexciv; Pictet and Campiche, ‘Terr. Crét. Ste. Croix’ (1869), p. 82, pl. ely, fig. 5.

2 See Deshayes’ fig. 3c.

’ The probability of this has been mentioned by EH. G. Skeat and V. Madsen, ‘Jur. Neoc. and
Gault Boulders in Denmark’ (‘ Danmarks geol. Undersog.,’ vol. ii, No. 8, 1898), p. 163,

4 «Gault de Cosne’ (1882), p. 83, pl. ix, figs. 21, 22.

GERVILLIA.

ol
“J

Campiche. The specimen figured by Pictet and Roux is not sufficiently perfect to
enable us to state whether it is specifically identical with G. sublanceolata, but since
Pictet, Renevier, and Campiche were acquainted with the type and other specimens
of G. alpina, and had also good specimens from Atherfield, we may feel every
confidence in their judgment in this matter.

.
“

Fia. 8.—Gervillia sublanceolata (d’Orbigny). Lower Greensand (Crackers), Atherfield. Sedgwick Museum.

Right and left valves of the same specimen. x }.

A young individual of this species from Atherfield was described and figured
by Forbes as Avicula lanceolata. This name, however, had previously been em-
ployed by Sowerby (1826) for a species from the Lias, and consequently d’Orbigny
altered the name of Forbes’ species to Avicula sublanceolata. Goldfuss (1836) had
also used the name Gervillia lanceolata for a species from the Middle Jurassic of
Wiirttemberg. Since d’Orbigny’s name has priority over Gervillia alpina of Pictet

78 CRETACEOUS LAMELLIBRANCHIA.

and Roux, the species now under consideration must be known as Gervillia sub-
lanceolata (d’Orbigny).

The young individuals of G. sublanceolata differ from the adults in that the
anterior part of the shell is relatively longer and more wing-like, the posterior ear
is more sharply limited and its growth-lines are concave posteriorly, and the valves
are more unequal (Plate X, figs. 14, 15).

G. sublanceolata belongs to Frech’s ‘Group of G. aviculoides.’ Frech gives a
ficure of the hinge and interior of a specimen from Atherfield.

I am greatly indebted to Professor Douvillé for the opportunity of seeing a
specimen of Gervillia anceps from Aube, and also for his kindness in comparing G.
sublanceolata with the specimens of G. anceps in the Heole des Mines, Paris.

Types.—One of the specimens figured by Sowerby (fig. 5) is in the British
Museum; the others (figs. 1—3) cannot be traced. Sowerby’s fig. 4 is from the
Corallian of Shotover, and does not belong to this species. Avicula lanceolata,
Forbes, from the Lower Greensand (probably Crackers) of Atherfield, is in the
Museum of the Geological Society (No. 2057). The type of Gervillia alpina came
from the Gault of Saxonet.

Distributionn—Lower Greensand (Crackers and Fitton’s Beds 20 and 45) of
Atherfield. Atherfield Beds of Sevenoaks.

Recorded by Topley from the Atherfield Beds of Haslemere, Peasmarsh, Shal-
ford, and Redhill; from the Hythe Beds of Hythe, Lympne, Maidstone, and
Pulborough; and from the Sandgate Beds of Sandgate, Folkestone, and Parham.

Upper Greensand (zone of Schlanbachia rostrata) of the Isle of Wight, Black-

down, and Haldon.

GERVILLIA TINGULOIDES, Forbes, 1845. Plate XI, figs. 2-8.

1845. Gervitiia LinauLoripgs, EH. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 246,
pl. iii, fig. 9.
— AvicuLA EPHEMERA, Forbes. Ibid., p. 247, pl. iii, fig. 6.
1846. GerRvILLIA LincuLoIpEs, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p.
485, pl. ecexevi, figs. 1—4.
1850. — _— ad’ Orbigny. Prodr. de Pal., vol. ii, p. 119.
— AvVICULA EPHEMERA, — Tbid., p. 119.
1854. Gervitiia LinauLorpes, J. Morris. Cat. Brit. Foss., ed. 2, p. 167.
— <Avicuta rpHemeERA, Morris. Ibid., p. 163.
1858. Guervitiia Linautorpes, FI’. J. Pictet and E. Renevier. Foss. Terr. Aptien
(Matér. Pal. Suisse, ser. 1),
p- 123, pl. xviii, figs. 3, 4.
1869. — _ FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse,
ser. 5), p. 91.

GERVILLIA. 79

Description.—Shell small, thin, elongate, compressed, very oblique, angular
anteriorly, truncated posteriorly. Left valve more convex than the right. Um-
bones almost terminal. Ligament area narrow, with four or five pits, one of which
is under the umbo. Anterior part of the shell very small, compressed. Median
part flattened. Postero-dorsal part relatively large, compressed, wing-like. On
the left valve a rounded ridge extends from the umbo to the postero-ventral angle ;
below this ridge the shell is bent sharply.

Surface smooth, or ornamented with concentric lines.

Measurements :
(1) (2) (3)
Length of hinge et 3 ae 15 ; 13 mm
Umbo to postero-ventral angle 23 , 29 ; Bot) tay

(1—3) Crackers, Atherfield.

Affinities. —G. recta, Meek and Hayden,’ from the Fox Hill Beds of the Upper
Missouri, is closely allied to this species. The imperfectly known Gervillia Reichi,
Romer,’ resembles G. linguloides, but appears to have the posterior wing more
distinctly limited.

In the form of its shell G. linguloides resembles some of the species of Pteria
which belong to the sub-genus Pseudoptera (see p. 63), but the presence of liga-
ment pits proves it to be a Gervillia.

Remarks.—Pictet and Renevier showed that Avicula ephemera, Forbes, is only
an internal cast of Gervillia linguloides.

This species occurs commonly in the Crackers of Atherfield and is gregarious.

Types.—From the Crackers of Atherfield, in the Museum of the Geological
Society (Nos. 2040, 2054). The types of Aviculu ephemera, also from Atherfield,
are in the same collection (Nos. 2051, 2052).

Distribution.—Lower Greensand (Crackers) of Atherfield. Recorded by Topley
from the Atherfield Clay of Peasemarsh and Shalford.

GERVILLIA ALaFoRMIS (Sowerby), 1819. Plate XI, figs. 9a-d, 10a-d, 11. Text-
figures 9-14.

1819. Moprona? anmrormis, J. Sowerby. Min. Conch., vol. iii, p. 93, pl. celi.

1835. Perna atirormis, Sowerby. Ibid., vol. vi, systematical index, p. 245.

1845. — atxrormis, E. Forbes. Quart. Journ. Geol. Soe., vol. i, p. 246, pl. iii,
fig, 2.

! «Proc. Acad. Nat. Sci. Philad.’ vol. xiii (1861), p. 441. F. B. Meek, ‘ Invert. Cret. and Tert. Foss
U. Missouri’ (1876), p. 66, pl. xxix, fig. la, b.

2 ‘Die Verstein. d. nord-deutsch. Kreidegeb.’ (1841), p. 64, pl. viii, fig. 14 (mamed G. Coltw on
pl. viii).

80 CRETACEOUS LAMELLIBRANCHIA.

1846. GerviniA ALmrormis, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ili, p. 484,
pl. ecexey, figs. 1—3.
1850. — aa d’Orbigny. Prodr. de Pal., vol. ii, p. 82.
1852. Avicuta Ruopant, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de
Gentve, p. 494, pl. xh,
fig. 2.
1854. GeERVILLIA AL@FoORMIS, J. Morris. Cat. Brit. Foss., ea 2, p. 167.
1853. Gervrirra aLirormis, F. J. Pictet and E. Renevier. Foss. Terr. Aptien (Matér.
Pal. Suisse, ser. 1), p.
120, pl. xviii, figs. 1, 2.
1865. — - H. Coquand. Mon. Aptien de Espagne, p. 144.
1869. 7 — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser.
5), p. 86, pl. elvi, fig. 1.
1871. GeERVILLEA — F. Stoliczka. Palzeont. Indica, Cret. Fauna §. India,
vol. iii, p. 399.

Description.—Shell thick, large, much inflated, triangular or rhombic, oblique.

)
i

al ave <2
\ | f \
ae

\
)

Fia. 9.—Gervillia aleformis (Sowerby). Lower Greensand (Crackers), Atherfield. Sedgwick Museum.
Dorsal view, showing the ligament area of the right valve. Natural size.
Anterior parts of both valves more or less nearly vertical to the plane of the valves.
Around the byssal opening the marginal parts of the valves are sometimes concave.
Umbones near the anterior extremity. Hinge-area large with large hgament pits
—usually five or six. Numerous narrow transverse teeth.

Left valve larger and more inflated than the right, with its umbo strongly
incurved. A very prominent, convex portion extends from the umbo to the
rounded postero-ventral extremity ; dorsally it bends anteriorly ; ventrally it has
a slight posterior curvature. This convex part is separated by a shallow depres-

GERVILLIA. 8]

sion from a small anterior portion, and by a linear depression from a very large
triangular posterior portion, which is flattened in small specimens but moderately
convex in older examples. This posterior portion has a wing-like projection in
young specimens, but in older forms its posterior border is nearly straight and
forms an obtuse angle with the hinge-line.

Right valve similar to the left, but smaller, less convex, with the posterior
portion more flattened, and with the umbo not incurved.

Ornamentation in the adult shell consists of numerous growth-lamelle.

the earlier part of the shell, and in young examples, there are a few rather strong,

On

broad, rounded radial ribs with a few smaller ribs between.

Fia. 10—Gervillia aleformis (Sowerby). Left valve of specimen shown in Fig.9. x 3.

Measurements :
(1) (2) (3)
Length of hinge ; 97 90) f 85 mm.
122 ; 130 eee 6 soe

Height (oblique)
(1—3) Crackers, Atherfield.

1 C I-A r 10 s ig
Affinities —This species presents some resemblance to G. allaudiensi

(Matheron') but is more inflated, less inequivalve, and less oblique.

Pictet and Campiche regarded the form figured as . alaforms by d Orbigny as
distinct from Sowerby’s G. alxformis, and they believed that the former was limited
to the Neocomian whereas the latter occurs in the Aptian. Some specimens from
the Perna-bed of Atherfield agree almost exactly with d’Orbigny’s figure, and I

1 «Catal. Foss. des Bouches-du-Rhone’ (1842), p. 175, pl. xvi, fig. 1; Pictet and Campiche, ‘ Terr

Crét. Ste. Croix’ (1869), p. 81, pl. ely, fig. 1. ‘

82 CRETACEOUS LAMELLIBRANCHIA.

Fia. 11.—Gervillia aleformis (Sowerby). Right valve, and umbo and ligament area of the left valve

of the specimen shown in figs. 9,10. x #.

Fras. 12, 18.—G@ervillia aleformis (Sowerby). Lower Greensand (Crackers), Atherfield. Sedgwick
Museum. 12. Left valve. 13. Right valve. x 3.

GERVILLIA. 83
cannot regard them as more than a variety in which the central convex part is
rather narrower and more elevated than usual (fig. 14).

Remarks.—G@. alxformis belongs to Frech’s! * Group of Gervillia Hartmanni,’ in
which the shell is obliquely rhombic and has numerous small teeth.

Young specimens of G. aleformis differ from older examples in having well-
marked radial ribs, in the valves being less inflated, and in the occurrence of a
wing-like projection on the posterior ear. They resemble the form described by
d@Orbigny as Avicula Cottaldina, but in the latter the radial ornamentation and
well-marked posterior wing are retained in the adult state, whereas they soon
become obsolete in G. aleformis. Iam not acquainted with the character of the
hinge of Avicula Cottaldina.

Fig. 14.—Gervillia aleformis (Sowerby). Lower Greensand (Perna-bed), Atherfield. Sedgwick Museum.
Left valve of a narrow variety. x j.

Type.—The type cannot be found; it came from the Lower Greensand (prob-
ably the Perna-bed) of Sandown, Isle of Wight.

Distribution —Perna-bed of Atherfield and Sandown. Crackers and Bed 11
(of Fitton) of Atherfield. Atherfield Clay of Haslemere. Hythe Beds of Hythe
and Lympne.

26 & wc ‘ Q_92
GeRvILLIA RosTRATA (Sowerby), 1836. Plate XI, figs. 12 a, b, 13-23.

1836. Perna rostrata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv., pp.
241, 342, pl. xvii, fig. 17.
1846. AvicuLa cenomanensts, A. d’Orbigny. Pal. Frang. Terr. Cret., vol. ili, p.
476, pl. ecexci, figs. 11—13.
1850. — — @’ Orbiqny. Prodr. de Pal., vol. ii, p. 167.

1 *Centralb. fiir Min.,’ ete. (1902), p. 613.

84. CRETACEOUS LAMELLIBRANCHIA.

1850. Prrna rostrata, d’Orbigny. Ibid., p. 168.
1854. Gervi~tLia — J. Morris. Cat. Brit. Foss., ed. 2, p. 168.
1871. Menina — F’. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. iii, p. 400.
2? 1895. Avricuna cf. ceNoMANENSIS, EH. Tiessen. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xlvui, p. 479.

Description.—Shell rather small, of moderate convexity, often very oblique,
triangular. Ventral and posterior margins rounded. Hinge-line long.

Left valve more convex than the right, with the umbo moderately imcurved.
The large, central, very convex portion is indistinctly separated from the large,
anterior, triangular, wing-like ear and from a narrow, flattened, obtusely triangular
posterior part.

Right valve similar to the left but less convex and with the umbo only slightly
incurved, and with the anterior ear more distinctly limited.

Surface of valves with narrow, regular growth-layers.

Measurements :

(1) (2) (3) (4) ()
Length of hinge . 21 20 20 : 18 ; 15 mm.
Height (oblique) . 25 28 24. ; 20 : Ue

(1—5) Greensand, Blackdown.

Affinities —Avicula cenomanensis, VOrbigny, from the Cenomanian of Le Mans,
appears to be identical with G. rostrata. In all the specimens of the latter which
I have seen, the terminal portion of the posterior wing is more or less imperfect,
but the growth-lines show that the posterior margin must have had the same form
as in d’Orbigny’s fig. 11.

Gervillia rostrata presents some resemblance to the young forms of G. alxformis
(p. 79) but is more oblique and without radial ribs, also the central convex
portion is less sharply marked off from the lateral parts, and the anterior ear is
larger.

G. rostrata is allied to G. tenwicostata, Pictet and Campiche (see below), but the
right valve is less flattened, and the concentric ornamentation appears to be less
developed—this, however, may be due to difference of preservation, since some
of the Blackdown specimens are nearly smooth whereas others show distinct
concentric ridges.

Remarks.—This species is moderately common at Blackdown but is usually
imperfectly preserved. An example from the Gault of Folkestone, recorded by
Price as Avicula cenomanensis, is probably referable to this species, but the greater
part of the shell has disappeared, leaving a mould of the right valve ; the specimen
is now in the Museum of Practical Geology (No. 1624).

The examples of G. rostrata show a considerable amount of variation in obliquity,

GERVILLIA. 85

and some of the less oblique specimens (Plate XI, figs. 17, 18) appear at first
sight to be distinct from the more abundant oblique forms, but there is a complete
transition between the extremes.

Distribution. Upper Greensand (zone of Schlanbachia rostrata) of Blackdown,
Haldon, and ? Devizes. ? Upper Gault (zone xi) of Folkestone.

GeERVILLIA, sp. Plate XI, figs. 24, 25.

Specimens from the Ferruginous Sands of Shanklin, which were collected by
the late C. J. A. Meer and are now in the Sedgwick Museum, resemble closely
G. rostrata and G. tenwicostata (Pictet and Campiche),' but the material at present
available is hardly sufficient to justify a definite conclusion as to their relationship.
The specimen from the Lower Greensand of Upware figured by Keeping? as
Perna sp. nov. resembles still more closely some examples of G. rostrata; the
original is in the collection of Mr. J. F. Walker.

GeERVILLIA Forsesiana, @’Orbigny, 1846. Plate XI, figs. 26, 27. Plate XII, figs. 1-5.

5

1826. GeRvILLiA soLeNnorpEs, J. de C. Sowerby. Min. Conch., vol. vi, p. 14, pl. dx,
figs. 1—3 (not 4).

1845. — — E. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 246.

1846. — Forspestana, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p
486, pl. ceexevi, figs. 5, 6.

1850. — — @Orbigny. Prodr. de Pal., vol. 11, p. 119.

1854. -- soLenorpgs, J. Morris. Cat. Brit. Foss., ed. 2, p. 168 (partim).

1897. _— Forsersiana, R. B. Newton. Proc. Dorset. Nat. Hist. and Antiq.

Field Club, vol. xvii, p. 87.

Description.—Shell compressed, slender, greatly elongated, sabre-shaped, taper-
ing posteriorly to a rounded or subtruncate extremity. Dorsal margin slightly
concave ; ventral margin convex, with a rather greater curvature than the dorsal
margin. Near the dorsal margin the valves are compressed rather abruptly, but
ventrally to this they are compressed gradually, giving rise to a knife-like edge.
Umbones terminal, acute. Posterior ear large, triangular, with its dorsal margin
straight or very slightly concave and its posterior margin curving backwards so as
to form an acute angle with the dorsal margin of the valve. ‘The ear is marked by
fine growth-lines parallel with its posterior border.

1 «Terr, Crét. Ste. Croix’ (1869), p. 88, pl. clvi, figs. 4, 5.
2 «Foss. Neoc. Upware and Brickhill’ (1883), p. 109, pl. v, fig. 3.

86 CRETACEOUS LAMELLIBRANCHIA.

Surface of valves smooth except for growth-ridges, of which the curved portions
near the dorsal margin are more distinct than the other portions.

Hinge with small transverse teeth at the anterior end and six or seven long
narrow oblique teeth near the posterior end—the latter decreasimg im length

posteriorly.
Measurements :
(1) (2) (3) (4)
Height’ 31 , 24 15 8 mm.
Length ° 2 oli82 . 125 : 74. a OW Gs

(1—4) Gault, Folkestone.

Affinities.—This species belongs to Frech’s* ‘ Group of Gervillia solenoides.’

The only localities given for G. Forbesiana by d’Orbigny are Shanklin and
Atherfield, and apparently his figured specimen came from the latter place. All
the examples from Shanklin are in the form of casts of which the posterior part is
usually missing; it is consequently difficult to make out their real characters, but
they probably belong to this species.

The examples found in the Gault and Upper Greensand differ somewhat from
the specimen figured by d’Orbigny. In the former the shell is less slender and
tapers more quickly posteriorly ; the posterior ear, however, agrees with d’Orbigny’s
figure.

A considerable number of examples of Gervillia from different localities and
horizons have been referred by various writers‘ to G. solenoides, Defrance,’ but
without seeing a large collection of those forms it is impossible to determine their
relationship to one another and to the examples here described. The figures given
by Defrance do not enable us to form a satisfactory idea of the characters of the
species ; in his original account (1820) he gave “ Ile d’Aix”’ as the locality, but in
his later remarks (1824) he states that the specimens came from the department
of Le Manche.

The Senonian specimens figured by d’Orbigny® as G. aviculoides (non G.
g Ny g

' From posterior end of hinge-line to opposite margin of valve.

2 From umbo to posterior extremity.

> *Centralb. fiir Min.,’ ete. (1902), p. 615.

4 Sowerby (1826), Goldfuss (1836), Reuss (1846), Miller (1847), d’Orbigny (1847), Alth (1850),
Zittel (1866), Favre (1869), Stoliczka (1871), Geinitz (1873), Brauns (1876), Fritsch (1877-93),
Notling (1885), Griepenkerl (1889), Holzapfel (1889), Liindgren (1894), Vogel (1895), Miller (1898),
G. oblonga, Bohm (1885).

5 «Dict. Sci. nat.,’ vol. xviii (1820), p. 503; vol. xxxii (1824), p. 316, pl. Ixxxvi, fig. 6.

5 «Pal. Frang. Terr. Crét.,’ vol. iii (1846), p. 489, pl. ecexevii, fig. 2 (and perhaps fig. 1). Prof.
M. Boule informs me that the original of fig. 1 cannot be found in the d’Orbigny collection, and that
the original of fig. 2 comes from Valognes (Manche).

PERNA. 87

aviculoides, Sowerby) were afterwards’ referred by that writer to G. solenoides,
Defrance, whilst the Cenomanian forms from Le Mans, also figured as @. solenoides,
were named” G. subaviculoides.

The examples of (. solenoides from the Senonian of Aachen figured by Holzapfel ®
differ from our specimens of G. Forbesiana in the greater height of the posterior
ear and in its indistinct separation from the rest of the valve, also in having a larger
apical angle.

Types.—Two of the specimens figured as G. solenoides by Sowerby (figs. 2, 3)
are in the British Museum and came from Shanklin. Another specimen figured by
Sowerby (fig. 1), from the Upper Greensand of Lyme Regis, is in the Museum of
the Geological Society of London (No. 1555), but is not recorded in Mr. Blake’s
“Tast of Types.” D’Orbigny’s type of G. Forbesiana apparently came from the
Crackers of Atherfield, but Professor Boule informs me that the specitnen cannot
now be found in the d’Orbigny Collection.

Distribution —Perna-bed, Atherfield Clay, and Crackers of Atherfield. Fitton’s
Bed 36 of Blackgang. Ferruginous Sands of Shanklin. Atherfield Beds of Peas-
marsh. Hythe Beds of Pulborough. Sandgate Beds of Parham Park.

Gault (zones ili to vii, and vin) of Folkestone. Zone of Hoplites interruptus of
Okeford Fitzpaine (Dorset). Cambridge Greensand (derived). Upper Greensand
of Blackdown.

Genus—Perrna, J. G. Bruguiére, 1789.
(‘ Eneye. Méthod., Vers,’ vol. i, p. xiii.)

Perna Mottert, Deshayes, 1842. ‘Text-figure 15.

1842. Prrna Muxuert, Deshayes in A. Leymerie. Mém. Soc. géol. de France, ser.
2, vol. v, p. 8, pl. xi, figs.

1—8.
1845. == a E. Forbes. Quart. Journ. Geol. Soc., vol. 1, p. 246, pl. i,
figs. 1-—4.
1846. — Mottern, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 496, pls.
cece, eccei, figs. 1—3.
1848. — Mouuuert, C. L. Koch. Paleontographica, vol. i, p. 171, pl. xxiv,

figs. 14—17.

1 «Prodr. de Pal.,’ vol. ii, 1850, p. 250.

2 Thid, vol. iii (1852), p. 72 (index); d’Orbigny, ‘ Pal. Frang. Terr. Crét.,” vol. iii (1846), p. 489,
pl. ceexevii, figs. 3, 4, 5. Prof. Boule informs me that these are from Le Mans, and are now in the
d’Orbigny collection.

3 *Mollusk. Aachen. Kreide’ (1889), p. 223, pl. xxiv, figs. 11, 12.

88 CRETACEOUS LAMELLIBRANCHIA.

1850. Perna Muuertt, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 82.

1854. — Mo.rert, J. Morris. Cat. Brit. Foss., ed. 2, p. 179.
1855. — Motern, G, Cotteau. Moll. Foss. de ’Yonne, p. 106.
1869. Motrert, FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix

(Mater. Pal. Suisse, ser.
5), p. 97, pl. elviii.
—- — Forsest, Pictet and Campiche. Tbid., p. 99, pl. elix.
1871. Metina Mouuert, F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. iii, p. 400.
1883. Perna Murueti, W. Keeping. Foss. ete., Neoc. Upware and Brickhill,

p. 150.
1884. ~- —-. O. Weerth. Die Fauna des Neocom. im Teutoburg. Wald.
(Paleont. Abhandl., vol. ii), p. 49.
1886. — (Mourerra) Munierr, P. Fischer. Manuel de Conch., p. 956,
fig. 725.
1895. — Motxert, F& Vogel. Holliindisch. Kreide, p. 55.

G. Maas. Zeitschr. der deutsch. geol. Gesellsch., vol.

xlvii, p. 267.
1896. — A. Wollemann. Ibid., vol. xlviii, p. 843.
1900. = = — Die Biv. u. Gastrop. d. deutsch. u. hol-
lind. Neocoms (Abhandl. d. k. preus-
sich. geol. Land., N. F., pt. 31), p. 60.

Description.—Shell large, thick, compressed, more or less quadrilateral, with
unequal angles. Hinge-lie long. Umbones almost terminal. Anterior part of
the shell sharply bent, and more or less nearly perpendicular to the plane of the
two valves; anterior marginal part more or less deeply concave. From the umbo
start two strong, broad, rounded folds; the anterior of these is near the anterior
margin and curves anteriorly, its extremity forming the antero-ventral angle; the
posterior fold at first curves ventrally and afterwards posteriorly, and its termina-
tion forms the postero-ventral angle. The part of the shell behind the posterior
fold is compressed and flattened and produced into a wing of varying length.
The junction of the two valves is sinuous, the anterior, the ventral, and the
posterior margins (between the angles) being concave on the right valve and
convex on the left.

The shell is ornamented with distinct growth ridges which bend ventrally in
passing over the folds and form a semicircular or semi-oval curve near the
hinge-line.

Measurements :

(1) (2) (3)
Length of hinge-line . . 128 ; 120 : 95 mm.
Height (from umbo to postero-
ventral angle). : = 114 135 130 ,,

(1—3) Perna-bed, Atherfield.

-

PERNA. 89

Affinities—The forms found in the Lower Greensand of England which had
been referred to Perna Mulleti by earlier writers were regarded as distinct by
Pictet and Campiche, and were named by them Perna Forbesi. They considered
that the latter were distinguished by the more prominent folds, the shorter and
more deeply concave anterior margin, and the longer posterior wing. An
examination of a number of specimens shows that these characters are variable,
and I am led to agree with Wollemann in thinking that the forms described by
Pictet and Campiche cannot be regarded as more than varieties of a variable
species.

Fic. 15.—Perna Mulleti, Deshayes. Lower Greensand (Perna-bed), Sandown. Sedgwick Museum. Left
valve x }. (The posterior wing is broken. Forbes gives a figure of a specimen in which the wing is
perfectly preserved.)

Perna Mulleti is the type of Fischer’s section Mulletia.

Type.—From the Neocomian of Vendeuvre. I have not seen the specimens

figured by Forbes.

Distribution —Perna-bed of Atherfield and Sandown. Atherfield Beds ot

Haslemere, Peasmarsh, Shalford, Redhill, Sevenoaks, and Hythe. Hythe Beds

, mm C
of Hythe (fide Topley). Lower Greensand of Potton and Upware. Tealby
Limestone (zone of B. brunsvicensis) of North Willingham. Speeton Clay of
Speeton.

90 CRETACEOUS LAMELLIBRANCHIA.

Perna Ricorpeana, d’Orbigny, 1846. 'Text-figures 16-18.

1846. Perna Ricorprana, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 494,
pl. ecexcix, figs. 1—3.

1850. — = @ Orbigny. Prodr. de Pal., vol. ii, p. 82.

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 179.

1855. ~ — G. Cotteaw. Moll. Foss. de ’Yonne, p. 107.

1858. — = FJ, Pictet and EL. Renevier. Foss. Terr. Aptien (Mater.
Pal. Suisse, ser. 1), p. 125.

1869. _ — FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse, ser.
5), p. 93, pl. elvii, fig. 1.

1869. — Frrront, Pictet and Campiche. Ibid., p. 95, pl. elvii, fig. 2.

1883. — Ricorprana, W. Keeping. Foss., etc., Neoc. Upware and Brickhill,
p- 150.

1900. — Rtcorpwana, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.

hollind. Neocoms (Abhandl. d. k.
preussisch, geol. Land., N. F., pt.
31), p. 61.

Fig. 16.— Perna Ricordeana, VOrbigny. Lower Greensand (Perna-bed), Atherfield. Museum of Practical
Geology, No. 12351. Left valve. x 4.

Description.—Shell large, thick, sub-quadrate, compressed; left valve more
convex than the right. Posterior margin slightly convex or nearly straight and
forming with the hinge-line an angle which is rather greater than a right-angle.

OO ee

titties ee |

PERNA. 9]

Ventral margin curved regularly. Dorsal part of anterior margin concave.
Valves moderately convex near the anterior margin, but flattened elsewhere.
Dorsal half or more of the anterior marginal parts concave and depressed. Umbones
sharp, close together, projecting beyond the rest of the anterior margin of the

valves.
Surface with growth-lamellz at more or less regular intervals.
Measurements :
(1) (2) (3)
Length of hinge : : 105 5 um : 75 mm.
Height of valve : : 140 ; 106 : NOME ee

(1—3) Perna-bed, Atherfield.

Fia. 17.—Perna Ricordeana, @Orbigny. Lower Greensand (Perna-bed), Atherfield. Sedgwick Museum.
Right valve and anterior view of both valves. x }.

Affinities —Examples of this species from the Lower Greensand of the Isle of
Wight were regarded by Pictet and Campiche as distinct from P. Ricordeana and
were described as Perna Fittoni. According to those writers the former is
distinguished from the latter chiefly by the wide separation of the umbones ; this
separation, however, seems to me to be due tothe thickening of the valves in old
age, such as may be seen not infrequently in Gervillia and other allied forms.
The postero-dorsal angle of the valve, according to d’Orbigny’s figure, appears to
be rather smaller in P. Ricordeana than in P. Fittoni, but the difference is not
great, and moreover, the outline of the shell and the size of this angle vary in
different specimens of P. Fittoni. P. Germani, Piectet and Campiche, is very
closely allied to P. Ricordeana.

92 CRETACEOUS LAMELLIBRANCHIA.

Types.—From the Neocomian of Seignelay, near Auxerre. The type of
P. Fittoni is from the Perna-bed of the Isle of Wight.

Distribution.—Lower Greensand (Perna-bed) of Atherfield. Tealby Limestone
(zone of Belemnites brunsvicensis) of North Willingham.

wean wee

-_---—— =

Fia. 18.—Perna Ricordeana, @Orbigny. Tealby Limestone, North Willingham. Sedgwick Museum.
Left valve. x 3.

Perna Ravuimiana, d’Orbigny, 1846. Plate XII, figs. 6, 7a, b, 8, 9.

1846. Perna Ravurniana, A. d’Orbigny. Pal. Frane. Terr. Crét., vol. iii, p. 497,
pl. cecei, figs. 4, 5.

1850. -— _- @Orbigny. Prodr. de Pal., vol. ii, p. 138.

1852. — — F. J. Pictet and W. Roux. Moll. Foss. Grés verts de
Gentve, p. 497, pl. xli, fig. 4.

1854. — _ J. Morris. Cat. Brit. Foss., ed. 2, p. 179.

1855. = — G. Cotteau. Moll. Foss. de l’Yonne, p. 107.

1869. _ — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse, ser.
5), p. 100, pl. elx, figs. 1, 2.

Description—Shell of moderate convexity, valves nearly equal, compressed
posteriorly, sub-rhomboidal, oblique, much higher than long; postero-ventral
margin rounded, anterior margin slightly concave, posterior margin slightly convex,

PERNA. 93

forming an obtuse angle with the hinge-line. Umbonal portion angular. Apical
angle small. Surface with growth-lines.
Measurements :}

(1) (2) (3) (4) (5)
Length ; : 35 J 34 Ct; 2A 1 23 . 11 mm.
Height ei Siee e 00) aes AO) On 6 Da ..

(1—3, 5) Cambridge Greensand.
(4) Lower Gault, Folkestone.

Affinities—This species is closely allied to P. Ricordeana (see above), but
appears to differ (1) in being relatively shorter and higher; (2) in its more obtuse
postero-dorsal angle; (8) in the less prominent umbones; (4) in the anterior
marginal parts (near the byssal opening) being less depressed; (5) in the smaller
size of the shell.

Remarks.—This species occurs commonly in the Cambridge Greensand in the
form of internal casts; these differ in outline from specimens with the shell pre-
served on account of the fact that the postero-dorsal part is missing—probably
owing to the two valves being in contact or almost in contact at this part. Even
when the shell is preserved, as in specimens from the Gault, some portion of the
postero-dorsal margin is frequently missing.

Types.—From the Albian of Avocourt (Meuse) and Escragnolles.

Distribution —Cambridge Greensand (derived, internal casts). Lower Gault of
Folkestone.

Perna optonca, Seeley, 1861. Text-figure 19 a.

1861. Perna optonaa, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. vii, p. 121,
pl. vi, fig. 6.

Remarks.—This species is known only from internal casts, and apparently
differs from P. Rauliniana in having a larger apical angle and in the smaller angle
formed by the hinge-line and the posterior margin. Some of the specimens, how-
ever, agree very closely with the figure of a cast of P. Rauliniana given by Pictet
and Campiche (pl. elx, fig. 2).

Seeley compared P. oblonga with P. subspathulata, Reuss,’ and P. lanceolata,
Geinitz (see below). It is distinguished from the former by its relatively greater
height, and from the latter by its larger apical angle.

1 The height in this case is measured from the umbo to the postero-ventral margin, and the

length is taken at right angles to the height.
2 «Die Verstein. der bihm. Kreideformat.,’ pt. ii (1846), p. 24, pl. xxxil, figs. 16, 17.

94 CRETACEOUS LAMELLIBRANCHIA.

Rounded depressions which are found commonly on the casts of this and some

other species of Perna from the Cambridge Greensand are regarded by Seeley as
evidence of the occurrence of pearls.

A specimen from the Gault (Plate XII, fig. 10) resembles P. oblonga, but is
more convex between the umbo and the postero-ventral extremity.
Type.—In the Sedgwick Museum.

Distribution —Cambridge Greensand (derived).

=~ =

Fia. 19.—Perna. Cambridge Greensand (derived). Internal casts. Sedgwick Museum.

Natural size,
except fig. p—a. Perna oblonga, Seeley. The Type—, c, Perna, sp. (referred to P. lanceolata, Geinitz,

by Seeley).—p, Perna semielliptica, Seeley. The Type.—x, Perna, sp. (regarded by Seeley as a variety
of P. lanceolata, Geinitz) x 4$.—», Perna, sp. (referred to P. subspathulata, Reuss, by Seeley).

Perna semretiiptica, Seeley, 1861. Text-figure 19 p.

1861. Perna semieiurprica, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. vii,

p. 121, pl. vi, fig. 7.
Remarks.—This is distinguished from P. Rauliniana (p. 92) by its relatively

greater length, larger apical angle, and more rounded outline.

PERNA. 95
Measurements :
(1) (2) (3)
Length 58 4G 32 mm.
Height F 87 f 70 : Aa es

(1—3) Cambridge Greensand.

Type.—F rom the Cambridge Greensand. Inthe Sedgwick Museum, Cambridge.
Distribution—Cambridge Greensand (derived, internal casts).

Perna, sp. Text-figures 19, B c.

1861. Perna Lancrouara, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. vii,
p. 122.

Remarks.—This species (figs. 19, ©) was referred by Professor Seeley to
Perna lanceolata, Geinitz,' and it presents a general resemblance to the examples
figured by Reuss and by d’Orbigny, but is less oblique. No satisfactory com-
parison, however, can be made, since the specimens from the Cambridge
Greensand are in the form of internal casts.

Some examples (fig. 19£) were named Perna lanceolata, var., by Seeley ; they
differ from Geinitz’s species in the postero-ventral part being more produced and
less rounded, so that the outline of the valve becomes more distinctly quadrate. By
this quadrilateral outline they are distinguished from P. Rauwliniana.

Distribution.—Cambridge Greensand (derived, internal casts).

Perna, sp. Text-figure 19 r.

1861. Perna supsparuuLatra, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 5, vol.
vii, p. 124.

Remarks.—Internal casts were regarded by Professor Seeley as examples of
P. subspathulata, Reuss,? but they appear to differ from the latter in their
greater convexity. The height is less and the length greater than in P. oblonga.

Distribution —Cambridge Greensand (derived).°

1 «Das Elbthalgeb. in Sachsen,’ pt. i (1873), p. 210, pl. xlvi, fig. 8. References to other figures
are given by Geinitz.

2 «Die Verstein. der bbhm. Kreideformat.,’ pt. ii (1846), p. 24, pl. xxxii, figs. 16, 17.

3 Avicula cuneata, Seeley, may be a Perna. Perna lissa, P. plana, and P. transversa, Seeley,
appear to be Inocerami. All four come from the Red Limestone of Hunstauton, Seeley, ‘Ann. Mag.
Nat. Hist.,’ ser. 3, vol. xiv (1864), p. 277, and vol. xvii (1866), pp. 178, 179.

96

Pinna Rosinatvina, d’Orbigny, 1844,

1839.

xv
—
oO
OO
bo

bbb)

1896.

1899.

1900.

1895.

CRETACEOUS LAMELLIBRANCHIA.

Family—PINNIDA, Gray.

Genus—Pinna, Linneus, 1758.

(‘Syst. Nat.,’ ed. 10, p. 707.)

Plate XII, figs. 11-15; Plate XIII, fig. 1.

Pinna rucGosa, F. A. Rimer. Die Verstein. d. nord-deutsch. Oolith.-geb.

Nachtrag., p. 32, pl. xviii, fig. 37 (non
rugosa, Schlotheim).

F. A. Réimer. Die Verstein. d. nord-deutsch. Kreidegeb.,

p- 65.

— Rosinarprina, A.d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 251,

pl. ecexxx, figs. 1-3.

— restituta, H. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 248.
— Rosrnauprna, A. d’Orbigny. Prodr. de Pal., vol. i, p. 80.

— suBruaosa, d’Orbigny. Ibid., p. 80.

— sutcirerA, J. Morris. Cat. Brit. Foss., ed. 2, p. 180.

— Rosrnauprna, G. Cotteau. Moll. Foss. de l’Yonne, p. 89.

F. J. Pictet and EH. Renevier. Foss. Terr. Aptien
(Matér. Pal. Suisse,
ser: 1); p; L17,
pl. xvi, fig. 5.

J. Villanova-y-Piera. Mem. geog.-agric. de Castellon,

pl. iu, fig. 17.
H. Coquand. Mon. Aptien de l Espagne, p. 143.
FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal.
Suisse, ser. 4), p. 532,
pl. exxxix, figs. 3-6.
P. de Loriol. Gault de Cosne, p. 82, pl. x, figs. 3-5.
W. Keeping. Foss., ete., Neoc. Upware and Brick-
hill, p. 110.
O. Weerth. Die Fauna des Neocom. im Teutoburg.
Walde (Palezont. Abhandl., vol. ii), p.48.
O. Behrendsen. Zeitschr. der deutsch. geol. Gesellsch.,
vol. xliv, p. 25.
F. Vogel. Hollindisch. Kreide, p. 55.
A. Wollemann. Zeitschr. der deutsch. geol. Gesellsch.,
vol. xlviii, p. 845.
G. Maas. Zeitschr. der deutsch. geol. Gesellsch.,
vol. li, p. 248.
A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.
hollind. Neocoms (Abhandl. d.
k. preussisch. geol. Land., N. F.,
pt. 31), p. 70.

Paleontographical Society, 1906.

A MONOGRAPH

OF THE

CRETACEOUS LAMELLIBRANCHIA

OF

ENGLAND.

BY

HENRY WOODS, M.A.

UNIVERSITY LECTURER IN PALZHOZOOLOGY, CAMBRIDGE

VOL. If, PART TT
PINNIDA ASTARTIDA, CARDITIDA, CRASSATELLITIDA.
AND CYPRINIDAL.

Paqaes 97—132; PLates XII—XIX.

LONDON:
PRINTED FOR THE PALHZONTOGRAPHICAL SOCIETY

1906,

PRINTED

LY ADLARD AND SON, LONDON AND DORKING.

.

¥

awe 7h

PINNA. 97

? 1888. Pryna Rozrnatpima, P. Choffat. Stratigr. et Paleont. d’Angola (Mém. Soc.
phys. et d’hist. nat. de Geneve, vol. xxx,
No. 2), p. 86, pl. v, figs. 4, 5.

? 1903. ~- — C. Burckhardt. Jura u. Kreidef. a. Cordillere (Palx-
ontographica, vol. 1), p. 79, pl. xv,
figs. 6, 7.

? 1905. — of. Roprnatprina, EF. Harbort. Fauna d. Schaumburg-Lippe’schen

Kreidemulde (Abhandl. d. k. preus-
sisch, geol. Landesanst., N.F., Heft
45), p. 47, pl. v, fig. 5; pl. vii,
figs. 2, 3.

Deseription.—Shell straight, much elongated ; pyramidal, slightly compressed ;
margins nearly straight; section sub-quadrangular.

Each valve is divided into two parts, which meet at an angle. The dorsal part
is smaller and more flattened than the ventral part, and is ornamented with from
6 to 8 or more ribs, which are narrow, strong, and nearly equi-distant. The ribs
are separated by broad, shallow, rounded depressions; both depressions and ribs
are crossed by very fine, somewhat irregular, concentric ridges, which sometimes
give a slightly serrated appearance to the ribs. The ventral part of each valve is
moderately convex, and its dorsal portion is ornamented with from 5 to 7 radial
ribs similar to those on the dorsal part of the valve, but decreasing in size ventrally;
the last one or two of these ribs sometimes become irregular and discontinuous.
These radial ribs and their interspaces are crossed by fine concentric ridges. The
ventral portion of the ventral part of the valve is ornamented with strong growth-
ridges or folds, which curve rapidly in the direction of the umbo, and form an
acute angle where they meet the ribs.

Measuremeits :

(1) (2)
Length a7 > 135 ., 94 mm.
Height ee \) ; Al

(1) Perna-bed, Atherfield.
(2) Crioceras-bed, Whale Chine.

Afinities—The figure of P. gracilis, Phillips,’ is not sufficiently good to enable
one to form a satisfactory idea of the character of the species, and the type cannot
now be found. But other specimens from Speeton, although very imperfectly
preserved, are sufficient to suggest that P. gracilis is probably identical with P.
Robinaldina.

It is suggested by Pictet and Campiche that P. tetragona, Sowerby,’ from the

1 «Geol. Yorks.’ (1829), p. 122, pl. ii, fig. 22.

2 ‘Min. Conch.,’ vol. iv (1821), p. 9, pl. ecexiii, fig. 1; Morris, ‘Cat. Brit. Foss.,’ ed. 2 (1854),
p. 180; P. subtetragona, d’Orbigny, ‘Prodr. de Pal.,’ vol. ii (1850), p. 165; Pictet and Campiche,

‘Terr. Crét. Ste. Croix’ (1867), p. 537; non P. tetragona, Brocchi, 1814.
13

98 CRETACEOUS LAMELLIBRANCHIA.

Upper Greensand of Devizes, is probably identical with P. Robinaldina. The
specimens from Devizes agree with those found at Blackdown in having the folds
on the ventral part of the valve rather more strongly marked than in P. Robinaldina
from the Lower Greensand. In other respects the Upper Greensand form does
not appear to differ from P. Robinaldina, and may be regarded as a variety of it,
P. Robinaldina var. tetragona, Sowerby.

P. Reynesi, Hébert and Munier-Chalmas,! is similar to P. Robinaldina, but
apparently differs in that the ribs on the ventral part of the shell are all smaller
than those on the dorsal part, and do not diminish gradually in size.

P. cretacea (Schlotheim)’ is closely related to P. Robinaldina, but appears
to be distinguished (1) by the ribs covering a larger proportion of the ventral
part of the shell and being of nearly uniform size, (2) by the growth-lines on
the ventral part being more nearly straight, (5) by the shell bemg usually more
elongate.

Remarks.—The specimens of Pinna found in the Gault of Folkestone and Black
Ven have usually been named P. tetragona. Their mode of preservation is more
or Jess unsatisfactory, owing to crushing and to the absence of some of the outer
layers of the shell, but after a close comparison with examples of P. Robinaldina
from the Lower Greensand I am unable to see any reason for regarding the former
as specifically distinct from the latter.

Pictet and Campiche thought that the examples from Blackdown were referable
to P. Robinaldina, differing only in having the folds on the ventral part of the shell
rather more strongly marked.

The specimens from the Lower Greensand of the Isle of Wight agree well with
the figures given by Pictet and Renevier and by Pictet and Campiche. The
number of ribs varies considerably, and in young specimens the apical angle is
smaller than in older examples.

A specimen from the Upper Greensand.of Ventnor, which has been referred *
to P. Reynesi, Hébert and Munier-Chalmas, is probably a crushed example of
P. Robinaldina.

T'ype.—The type of P. rugosa came from the Hils-conglomerate of Osterwald.
The type of P. tetragona, Sowerby, came from the Upper Greensand of Devizes
and is now in the British Museum.

Distribution —Perna-bed, Crackers, and Fitton’s Beds 16 and 38, of Atherfield.
Ferruginous Sands of Shanklin. Atherfield Beds of Redhill, Reigate. Sandgate
Beds of Parham Park. Lower Greensand of Brickhill. PSpeeton Clay (zone
of Belemnites brunsvicensis) of Speeton. Gault of Folkestone and Black Ven.

1 «Ann. Sciences géol.,’ vol. vi (1875), p. 118, pl. v, fig. 10.

* Geinitz, ‘Das Elbthalgeb.’ (Palzontographica, vol. xx, pt. 2, 1873), p. 54, pl. xiv, figs. 2, 3.
* Jukes-Browne, ‘Cret. Rocks of Britain,’ vol. i (1900), p. 470,

PINNA. 99

Upper Greensand (zone of Schlenbachia rostrata) of Blackdown, Devizes, and
Ventnor.!

Pinna, sp. Plate XIII, figs. 2, 3.

Some specimens of Pinna found in the Gault of Folkestone differ from
P. Robinaldina in having smaller and more numerous ribs, which are crossed at
regular intervals by narrow concentric ridges.

Pinna tecuLata, Etheridge, 1881.

1881. Pinna reGunata, R. Etheridge, in Penning and Jukes-Browne’s Geol. Cam-
bridge (Mem. Geol. Survey), p. 142, pl. i,
fig. 2.

Remarks.—This species is known only by the type and a few fragmentary
specimens. The type shows the interior of a right valve. The ornamentation
appears to be similar to the form from the Gault described above. On the dorsal
half of the valve there are about 18 narrow ribs, which are crossed at regular
intervals by concentric ridges, giving rise to a fimbriated appearance. About
similar ribs are found on the dorsal part of the ventral half of the valve, below
which are strongly curved growth-ridges.

T'ype.—tIn the Sedgwick Museum, Cambridge.

Distribution. —Totternhoe Stone (zone of Holaster subglobosus) of Burwell.

Pinna pecussara, Goldfuss, 1837. Plate XIII, figs. 4a-c, 5, 6. Plate XIV, fig. 1.

1833. Pinna sutcata, S. Woodward. Geol. Norfolk, p. 47, pl. v, fig. 23.
1837. — opecussata, A. Goldfuss. Petref. Germ., vol. ii, p. 166, pl. exxviil,
figs. 1, 2.
-— — compressa, Goldfuss. Ibid., p. 167, pl. exxviii, fig. 4.
P 1840. — pyramipauis, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 2, p. 55, pl. x, fig. Ie
= — compressa, Geinitz. Ibid, p. 59.
1841. — yenestrata, F. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p. 65, pl. viii, fig. 22.
= — pecussata, Rimer. Ibid., p. 65.
1846. — pyramipauis, H. B. Geinitz. Grundr. d. Verstein., p. 451.

' T have not seen any specimen of Pinna? crassa, Fitton, * Trans. Geol. Soc.,’ ser. 2, vol. iv (1836),

p- 130; Morris, ‘Cat. Brit. Foss.,’ p. 180.

100 CRETACEOUS LAMELLIBRANCHIA.

1846. Pinna pecussata, A. EF. Reuss. Die Verstein. der bihm. Kreideformat.,
pt. 2, p. 14, pl. xxxvii, figs. 1, 2.
1850. ~- -- A. d@Orbigny. Prodr. de Pal., vol. ii, p. 165.
— — renestrata, d’Orbigny. LIbid., p. 246.
—- — ovecussata, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 355 (p.
386, ed. 2), pl. xxviii,
fig. 20.
— — opinuvrana, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in
Deutschland, p. 166.
_ — FENESTRATA, Geinitz. Ibid., p. 166.

1854. — opecussata, J. Morris. Cat. Brit. Foss., ed. 2, p. 180.
— — suteara, Morris. Ibid., p. 180.
1873. — overcussata, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palonto-

graphica, vol. xx), pt. 1, p. 211, pl. xlvu,
figs. 4,5; pt. ii, p. 53, pl. xv, figs. 2,5;
pl. xvi, fig. 1.
1877. — — A. Fritsch. Stud. im Gebiete der bohm. Kreideformat.,
u. Weissenberg. u. Malnitz. Schicht., p.
120, fig. 86.

1883. _ — Fritsch. Ubid., ii. Iserschicht., p. 104.
1888. -- _- G. Miller. Mollusk. d. untersen. v. Braunschweig (Jahrb.
d. k. preussisch. geol. Landesanst. fiir 1887),
p. 420.
1889. — — Fritsch. Stud. im Gebiete der bohm. Kreideformat.,
iv. Teplitz. Schicht., p. 79.
Y 1890. — - M. Blanckenhorn. Beitr. z. Geol. Syriens: Kreidesyst.
in Mittel u. Nord-Syrien, p. 80.
1893. — — Fritsch. Stud. im Gebiete der bohm. Kreideformat.,
vy. Priesen. Schicht., p. 94.
1897. _ -- — Tbid., vi. Chlomek. Schicht., p. 57.
? 1894. — cf. pecussara, A. Hennig. Om Ahussandst. (Geol. Foren. i Stock-
holm Foérhandl., vol. xvi), p. 522.
1902. — opecussata, J. P. J. Ravn. Mollusk. i Danmarks Kridtaflej., i.

Lamellibr., p. 104.

Non 1846. — = E. Forbes. Trans. Geol. Soc., ser. 2, vol. vii, p. 153
(= P. arata, Forbes).

Description.—Shell moderately elongate, triangular, laterally compressed,
section rhombic, but becoming lenticular in the later portion. Dorsal margin
straight, ventral margin shghtly curved.

Each valve is divided into two nearly equal parts. The dorsal part is flattened
and bears from 7 to 9 strong rounded ribs, separated by broad, shallow,
rounded depressions. The distance between the ribs increases in passing from the
apex to the posterior extremity. In well-preserved specimens linear ridges are
seen crossing the ribs and interspaces at regular intervals. The dorsal portion of

PINNA. 101

the ventral part of the valve bears from 5 to 7 ribs similar to those on the

dorsal part and of nearly uniform size, with transverse linear ridges. On the

ventral portion of the ventral part of the valve there are strong ridges or folds

which form an acute angle with the last rib, and curve slightly towards the umbo.
Measurements (approximate) :

(1) (2) (3)
Length 3 125 . LA7 " 120 mm.
Height ; 66 : 69 , 0) ome

(1) Chalk Marl, Folkestone.
(2) Chalk, Newtimber (Sussex).
(3) Chalk, Trimingham.

Remarks.—Most of the specimens of Pinna from the Chalk are very imperfectly
preserved, and it is not unlikely that better material would show that more than
one species could be distinguished.

In the examples from Trimingham the ribs are rather broader and more
rounded than in most of the specimens found at lower horizons.

Affinities.—This species is less elongate than P. cretacea (Schlotheim),' and
has the ridges on the ventral part of the valves more distinctly curved than in
that form. It has a larger apical angle than P. Robinaldina (see p. 96); also the
shell is rather more compressed, and the ribs on the ventral part do not decrease
regularly in size as they do in P. Robinaldina.

P. sulcata, Woodward (Plate XIV, fig. 1), from the Norwich Chalk, as was
suggested by J. de C. Sowerby, does not differ from TP’. decussata. Woodward's
name is prior to that of Goldfuss, but since the original figure was scarcely
sufficient for the recognition of the species and was not accompanied by any
description, I do not think it is desirable that the well-known name LP. decussata
should be displaced by P. suleata.

Most of the English specimens of P. decussatu agree better with the figures
given by Geinitz (1873) than with those of Goldfuss and Reuss. But the example
figured by Dixon seems to be very similar to the types of Goldfuss.

Types—From the Quadersandstone of Haltern (Westphalia) and Schandau
(Saxony). The specimen figured by Dixon cannot be found. The type of J’.
sulcata is in the Norwich Museum.

Distribution.—Chalk Marl of Ventnor and Folkestone. Terebratulina zone of
Arn Hill near Warminster. Zone of Holaster planus of Balsham. Chalk of New-
timber. Zone of Micraster cor-anguinum of Charlton and Gravesend. Upper Chalk
(zone of M. cor-testudinarium or M. cor-anguinum) of Swaffham, Norfolk. (?) Zone
of Actinocamae quadratus of East Harnham near Salisbury. Zone of Belemnitella
mucronata of Norwich. Chalk of Trimingham.

1 Geinita, ‘Das Elbthalgeb.,’ pt. ii (1873), p. 54, pl. xiv, figs. 2, 3.

102 CRETACEOUS LAMELLIBRANCHIA.

Family—ASTARTIDA, Gray.
Grenus—AstariE, J. Sowerby, 1816.
(‘ Min. Conch.,’ vol. ii, p. 85.)
ASTARTE ELONGATA, @Orbigny, 1844. Plate XIV, figs. 2a, b, 3.
1842. AsrarTE opLoNnGATA, Deshayes in A. Leymerie. Meém. Soc. géol. de France,

ser. 2, vol. v, pp. 5, 24, pl. vi, fig. 1
(non oblonga, Sowerby, 1826).

1844. — pLoneata, A.d’Orbiqny. Pal. Franc. Terr. Crét., vol. iii, p. 68, pl.
: eclxii, figs. 8—11.

1850. — — d’Orbigny. Prodr. de Pal., vol. ii, p. 77.

1855. — — G, Cotteau. Moll. Foss. de ’Yonne, p. 69.

1866. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Mater. Pal. Suisse, ser.
4), p. 310, pl. exxiv, figs. 8, 9.

1868. — = P. de Loriol. Valangien d@Arzier, p. 28, pl. u1, fig. 7.

1871. — -- F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. iii, p. 285.

1900. — _ A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. hol-

land. Neocoms (Abhandl. d. k.
preussisch. geol. Land., N. F., pt.
31), p. 102.

Description.—Shell thick, elongate, rounded-oblong or oval, convex, compressed,
very inequilateral. Postero-dorsal margin curving ventrally to jom the obtuse
and slightly curving posterior margin. Postero-ventral extremity rounded. Ven-
tral margin nearly straight. Anterior margin rounded. Umbones small, with an
indistinct keel passing from them towards the postero-ventral extremity. Lunule
narrow.

Ornamentation consists of strong concentric ribs, somewhat unequal in size, and
separated by narrow grooves. Margins of valves crenulated.

Length 21 mm.; height 22 mm.

Affinities —Astarte cingulata, Geinitz,’ from the Cenomanian of Plauen, is
probably identical with this species.

A, elongata is easily distinguished from other Cretaceous species by its elongate
form.

Remarks.—The only specimens seen are in the Museum of Practical Geology.

1 «Das Elbthalgeb. in Sachsen’ (Paleontographica, vol. xx, pt. i, 1873), p. 226, pl. 1, fig. 8. Non
A. cingulata, Contejean, ‘ Kimmérid. de Montbéliard’ (1859), p. 267, pl. xi, figs. 5—7.

ASTARTE. 103

One has the shell preserved, the others are internal casts showing deep muscular
impressions.

Types.—Leymerie’s specimens came from the Lower Neocomian of Avalleur,
Chenay, and Marolles (Aube). D’Orbigny records specimens from the Lower
Neocomian of St. Sauveur (Yonne). Pictet and Campiche figure specimens from
the Valanginian of Ste. Croix.

Distvibution.—Lower Greensand of Seend.

ASTARTE SUBACUTA, @’Orbigny, 1850. Plate XIV, figs. 4—6.

1844, AsTarTe carinata, A. d’Orbigny. Pal. Frang. Terr, Crét., vol. iii, p. 63,
pl. celxii, figs. 1-3. (non A. carinata,
Phillips, 1829.)

1847. — acuta, d’Orbigny. Ibid., p. 759. (non A. acuta, Reuss, 1846.)

1850. == supacuta, d’Orbigny. Prodr. de Pal., vol. ii, p. 77.

1866. = = F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p- 318.

1900 — — A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.

hollind. Neocoms (Abhandl. d.
k. preussisch. geol. Land., N. F.,
pt. 31), p. 99.

Description—Shell triangular, much compressed, length greater than height,
slightly inequilateral. Antero-dorsal margin long and concave. Postero-dorsal
margin longer than the antero-dorsal, and either concave or nearly straight. Both
of these margins form obtuse angles with the well-rounded margin of the ventral
half of the shell. Umbones very acute, projecting, often nearly median and not
curved. Lunule narrow, with a sharp edge. Escutcheon very narrow.

Ornamentation consists of prominent concentric ribs separated by broad inter-
spaces. The distance between the ribs increases in passing from the umbo
ventrally. Margins of valves crenulated.

Measurements :

(1) (2)
Length : 14. : 10 mm.
Height ‘ td : Sure

(1, 2) Perna-bed, East Shalford.

Affinities. —A. subacuta is distinguished from the other Cretaceous species by
its acute umbones and flattened valves.
Remarks.—The only specimens which I have seen are in the Meyer Collection,

Sedgwick Museum.

104. CRETACEOUS LAMELLIBRANCHIA.

T'ype.—From the Neocomian of Brienne (Aube).
Distribution.—Perna-bed of East Shalford. Atherfield Beds of Sevenoaks.

Astarve sinvata, d’Orbigny, 1844. Plate XIV, figs. 7—9.

1844. Asrarre stnvava, A. d’Orbiqny. Pal. France. Terr. Crét., vol. iii, p. 69, pl.
eelxiv, figs. 1—3.
1850. _— — Wd Orbigny. Prodr. de Pal., vol. ii, p. 118.
1856. — — F.J. Pictet and E. Renevier. Foss. Terr. Aptien (Matér.
Pal. Suisse, ser. 1), p. 89,
pl. x, fig. 5.
1866. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal.
Suisse, ser. 4), p. 311.

1871. = — F. Stoliczka. Paleont. Indica, Cret. Fauna S. India,
vol. ii, pp. 251, 285.
1895. ~- — G. Maas. Zeitschr. d. deutsch. geol. Gesellsch., vol.
xlvii, p. 261.
1900. — — A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.

holliind. Neocoms (Abhandl. d. k.
preussisch. geol. Land., N. F., pt. 31),
p- 100.

Description.—Shell sub-quadrate, rounded ventrally, truncated posteriorly,
longer than high, shghtly or moderately inequilateral, much compressed. A furrow
extends from just behind the umbo to the simuosity on the posterior margin, and
cuts off a triangular, flattened, postero-dorsal part of the valve. Antero-dorsal
margin nearly straight. Anterior margin rounded, passing gradually imto the
curved ventral margin. Posterior margin with a sinuosity above the postero-
ventral angle. Postero-dorsal margin straight or slightly concave, longer than the
antero-dorsal margin, and forming an angle with the posterior margin. Umbones
pointed, inconspicuous. Lunule and escutcheon long, narrow, with sharp edges
which have tooth-like projections where the ribs end.

Ornamentation consists of rounded, concentric ribs separated by shallow
furrows. ‘The ribs are rather stronger on the posterior than on the anterior part
of the shell, and are sinuous where they cross the posterior furrow. Smaller ribs
are present on the main ribs and furrows.

Measurements :

(1) (2)
Length . : ; 16 : : 15 mm.
Height . : : Tulpsy : 14.
Thickness : ; 4:

(1, 2) Crackers, Atherfield.

ASTARTE. 105

Affinities.—A. sinuata is distinguished from other Cretaceous species of Astarte
by the furrow passing from the umbo to the posterior margin. Conrad! thought
that this species might belong to his genus Lirodiseus. Iam unable to express an
opinion on this matter, since I have seen only three examples, none of which shows
the hinge, nor is it seen in the figures given by previous writers.

T'ype-—From the Aptian of Marolles (Aube).

Distribution —Lower Greensand (Crackers) of Atherfield. Recorded by Pictet
and Renevier from the Lower Greensand of Peasmarsh.

ASTARTE UPWARENSIS, sp. nov. Plate XIV, figs. 10 a-c, 11a, b, 12.

1883, Asrarre, sp. nov., W. Keeping. Foss., etc., Neoc. Upware and Brickhill,
p- 122, pl. vi, fig. 9.

Description Shell ovate, a little higher than long, moderately and evenly
inflated, moderately (or sometimes only slightly) inequilateral. Dorsal half narrow-
ing gradually to the umbo; ventral half larger and with evenly-rounded margin.
Antero-dorsal border shghtly concave; postero-dorsal border long and convex.
Umbones curving forward. Lunule large, ovate, depressed, with a sharp border.
Escutcheon lanceolate, with a sharp edge.

Ornamentation consists of many flattened, imconspicuous, concentric ribs
separated by linear grooves.

Measurements :

(1) (2) (3) (4) (5)
Length . 24. 21 ‘ 19 : 14. ; 13 mm.
Height 25 Nas ee 21 . 15 : 14 ,,

(1-5) Lower Greensand, Upware.

Affinities—This species presents some resemblance to A. valangiensis, Pictet
and Campiche,” but its dorsal half is not so narrow and pointed, and the antero-
dorsal margin is less concave. It is also similar to A. Rhodani, Pictet and
Campiche,* from the Gault of Cosne, but the umbones are less prominent.

Astarte upwarensis is distinguished from A. circularis, Guéranger,’ by its ovate
outline and greater height.

T'ype.—Of the specimens of this species which were figured by W. Keeping as

1 «Amer. Journ. Conch.,’ vol. v (1869), p. 46.

‘Terr. Crét. Ste. Croix’ (Matér. Pal. Suisse, ser. 4, 1866), p. 303, pl. exxiii, figs, 3, 4.
3 De Loriol, ‘ Gault de Cosne ’ (1882), p. 94, pl. xii, figs. 1-7.

4+ «Album Paléont. de la Sarthe * (1867), p. 12, pl. xv, fig. 12, pl. xvi, figs. 7, 8.

ie)

14.

106 CRETACEOUS LAMELLIBRANCHIA.

Astarte, sp. nov., one is in the Sedgwick Museum (fig. 9), the other in Mr. J. F.
Walker’s collection (fig. 9).
Distribution.—Lower Greensand of Upware.

ASTARIE SENECTA, sp. nov. [ex Bean MS.] Plate XIV, figs. 13-20.

1889. AsrarrE senecra [Bean MS.] G. W. Lamplugh. Quart. Journ. Geol. Soe.,
vol. xlv, p. 616.

Description.—Shell subtriangular, or approaching subquadrangular, sometimes
rounded, rather compressed, usually very imequilateral; height usually a little
greater than length. Anterior margin rounded, ventral margin curving slightly
and often forming a rounded angle with the posterior margin, which is slightly
curved and usually makes an obtuse angle with the postero-dorsal margin.
Umbones small, curving forwards. Lunule ovate, deep, with a sharp border.
Escutcheon narrow, deep, with a sharp border.

Ornamentation consists of strong concentric ribs, with sharp summits, separated
by broad furrows, on both of which are numerous small ribs. The ribs bend
sharply in passing on to the postero-dorsal part of the valve, and cut the postero-
dorsal margin obliquely. Margins of valves strongly crenulated.

Measurements :

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (1d)
Length > 2d 22) 21 19 G3 260 O25, Zoe eon: 21 mm.
Height . 25 20 19 © A 4 SOR o ee 22e R258 eA eee

(1-5) Speeton Clay, Speeton.
(6-11) Claxby Ironstone, Benniworth Haven.

Affinities—Astarte veneris, Kichwald,' is similar to this species, but has a
deeper and larger lunule, more prominent umbones, less compressed valves, and
more slender ribs. Specimens of A. veneris from the ‘ Volgian’ of Moscow are
in Mr. Lamplugh’s collection.

Remarks.—This species has been known to collectors for a long time, and has
appeared in lists of fossils under the name Astarte senecta, Bean MS., but has not
hitherto been described and figured.

The specimens from the Claxby Ironstone are, as a rule, more rounded in
outline than those from Speeton, and their ornamentation is not so well preserved
on account of the difficulty of separating the shells from the hard matrix in which
they are found.

1 D’Orbigny, in Murchison, de Verneuil, and de Keyserling, ‘ Géol. Russ. d’ Europe,’ vol. ii (1845),
p. 456, pl. xxxviii, figs. 21, 22. :

ASTARTE. 107

Distribution.—Zone of Belemnites lateralis: in the Speeton Clay of Speeton
and the Claxby Ironstone of Benniworth Haven.

AsTarTE, sp. Plate XIV, fig. 21.

Deseription.—Shell oval, moderately convex, slightly inequilateral, length
greater than height. Antero-dorsal margin concave. Anterior margin rounded,
passing gradually to the curved ventral margin. Postero-dorsal margin convex,
forming a rounded angle with the posterior margin. Umbo pointed.

Ornamentation consists of about 15 strong, rounded, concentric ribs separated
by rounded furrows of greater breadth. Fine concentric ridges occur on both ribs
and furrows. The ribs cut the postero-dorsal margin at a large angle; they are
more widely separated on the dorsal than on the ventral half of the valve.

Length 12°5 mm.; height, 11:2 mm.

Remarks.—This species is known by a single right valve only. The ornamenta-
tion is somewhat similar to that of A. senecta, but the shell is more oval and less
mequilateral, also the ribs are more numerous and form a larger angle with the
postero-dorsal margin.

Distribution —Speeton Clay of Speeton.

ASTARTE CANTABRIGIENSIS, Sp. nov. Plate XIV, figs. 22a, b, 25a, b, 24.

1883. AsrarTeE suppENTATA, W. Keeping. Foss., etc., Neoc. Upware and Brick-
hill, p. 122, pl. vi, fig. 11 (mon
Romer).

Description.—Shell subquadrate, longer than high, very inequilateral, moderately
inflated, with the greatest convexity between the umbo and the postero-yentral
angle. Postero-dorsal margin long, slightly convex, forming an obtuse angle with
the truncated posterior margin, and a blunt angle where it joins the slightly convex
ventral margin. Anterior margin rounded. Lunule deep, ovate, distinctly limited.
Escutcheon deep, with a sharp edge.

Ornamentation consists of strong concentric ribs bearing finer ribs.

Measurements :
(1) (2) (3) (4) (5) (6) (7 (8)
Length ; 175 15 15 14 14 13°5 13 12 mm.
Height j 16 13335) 13 iS ily 12:5 15" -LOtay

(1-8) Lower Greensand, Upware.

108 CRETACEOUS LAMELLIBRANCHIA.

Affinities. —This species was identified by W. Keeping with A. subdentata,
Romer, from the Neocomian of Brunswick. I have submitted photographs of
the British fossil to Dr. A. Wollemann and he agrees with me in thinking that it
is quite distinct from A. subdentata. In the latter the shell is smaller, the valves are
much flatter and more elongate, and the umbones are more pointed and less
anterior in position.

The ornamentation, when well preserved, is somewhat similar to that of A.
senecta (see above), but the shell is more inequilateral, more nearly quadrate in
outline, and the postero-dorsal part is more compressed.

Remarl:s.—The ornamentation is often imperfectly preserved, and in some cases
it has almost entirely disappeared. The hinge has not been seen.

Type.—The specimen figured by Keeping is in the Sedgwick Museum, Cam-
bridge.

Distribution —Lower Greensand of Upware.

ASTARTE CLAXBIENSIS, sp. nov. Plate XIV, figs. 25-28.

Deseription.—Shell small, thick, oval, longer than high, inflated, shghtly inequi-
lateral. Antero-dorsal margin concave, postero-dorsal slightly convex. Anterior
margin well rounded. Ventral and posterior margins formimg a regular curve.
Umbones prominent, close together, nearly median, curved greatly inwards and
slightly forwards. Lunule large, ovate, with sharp edges. Escutcheon lanceolate,
smooth, distinctly limited.

Ornamentation consists of strong, narrow, concentric ribs, separated by broad,
deep furrows. Left valve with two stout cardinal teeth and a tooth at the margin
of the lunule. Margins of valves coarsely crenulate.

Measurements :

(1) (2) (3) (4) (5)
Length : 112 5 ial - 10 ; 9 : 8 mm.
Height : 10:54 4; 10 ’ 9 ; 8°25 . (ies

(1-8, 5) Claxby Ironstone, Benniworth Haven.
(4) Spilsby Sandstone, Spilsby.

Affinities.—Astarte claxbiensis shows considerable resemblance to certain species
found in the Jurassic rocks; thus Astarte robusta, Lycett,’ from the Cornbrash, seems
to differ only in having the valves more elongate and the umbonal parts narrower.

1 «Verstein. norddeutsch. Kreidegeb.’ (1841), p. 71, pl. ix, fig. 9. Wollemann, ‘ Die Bivalven u.

Gasterop. d, deutsch. u. holliind. Neocoms’ (1900), p. 98, pl. v, fig. 2.
* «Suppl. Mon. Mollusca Great Ool.,’ ete. (1863), p. 74, pl. xxxv, fig. 6.

ASTARTE. 109

A. cordata, Trautschold,' is another example of the same type. A. Sauvagei, de
Loriol,” from the Sequanian, is also similar to A. clawbiensis, but appears to be less
elongate.

Distribution.—Spilsby Sandstone (zone of Belemnites lateralis) of Spilsby.
Claxby Ironstone (zone of B. lateralis) of Benniworth Haven.

Astarte suscostata, @’Orbigny, 1850. Plate XIV, figs. 29-36.

1842. AsrartE naticosta, Deshayes. In A. Leymerie, Mém. Soc. géol. de France,
ser. 2, vol. v, p. 4, pl. iv, figs. 4, 5

(non A. laticosta, Deshayes, 1839).
184-4. — strrato-costaTa, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii,
p. 64, pl. celxii, figs. 7-9
(non A. striato-costata, Romer,

1836).
1845. Venus (?) [srrraro-costata |, EH. Forbes. Quart. Journ. Geol. Soe., vol. i,
p- 241.
1850. AstartTe suscosrara, d’Orbigny. Prodr. de Pal., vol. ii, p. 77.
1854. — stRraTo-cosTaTa, J. Morris. Cat. Brit. Foss., ed. 2, p. 187.
1855. — suBcostaTa, G. Cotteau. Moll. Foss. de l’Yonne, p. 70.
1856. — Laticosta, F. J. Pictet and E. Renevier. Foss. Terr. Aptien
(Matér. Pal. Suisse, ser. 1), p. 88,
pl. x, fig. 2.
1865. - Leymeru, K. A. Zittel. Die} Bivalv. d. Gosaugeb. (Denkschr. d. k.

Akad. Wien, Math.-nat. Classe, vol.
xxiv), p. 156.

1865. — Laticosta, H. Coquand. Mon. Aptien de l’Espagne, p. 126.
1866. — supcostata, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4), p. 307.
? 1868. — strraTo-costata, BE. Hichwald. Lethza Rossica, vol. ii, p. 624.
? 1868. — natricosta, Hichwald. Tbid., p. 628.
P 1900. — Leymern, G. Miiller. Deutsch-Ost-Afrika, vol. vii, p. 552,
pl. xxii, figs. 4, 5.
1905. — suscostata, E. Harbort. Die Fauna der Schaumberg-Lippe’schen

Kreidemulde, p. 60, pl. iv, fig. 6.

Description.—Shell small, usually rather convex, subquadrate or subtriangular,
moderately or very inequilateral. Antero-dorsal margin concave. Anterior and
yentral margins rounded. Postero-dorsal margin long, nearly straight, forming an

1 GC, Rouillier, ‘Bull. Soc. Nat. Moscou,’ vol. xix, pt. 2 (1846), pl. v, fig. 15; pl. &, fig. 1; vol. xxi,
pt. 1 (1848), pp. 274, 275. Trautschold, Ibid., vol. xxxiii (1860), p. 347.

2 De Loriol and Pellat, ‘Mon. Paléont. et Géol. étages sup. Jurass. de Boulogne-sur-Mer’ (1874),
p- 96, pl. xv, figs. 33, 34.

110 CRETACEOUS LAMELLIBRANCHIA.

angle with the posterior margin, which is more or less truncated. Umbones
inconspicuous. Lunule smooth, ovate, rather broad, with a sharp edge. Escutcheon
smooth, deep, long.

Ornamentation consists of 7 to 9 sharp, prominent, concentric ribs, with steep
dorsal and gentle ventral slopes. Interspaces broad. Between the ribs there are
three or four very small concentric ribs and numerous fine radial strie.

Measurements :

(1) (2) (3) (4)
Length : ve , 6 55 5 mm.
Height ‘ 5 ; 5 45 ! Ard ,,

(1) Atherfield Beds, Sevenoaks.
(2) Atherfield Beds, Peasmarsh.
(3, 4) Perna-bed, Hast Shalford.

Affinities.—This species resembles Astarte formosa (see p. 112) but is larger,
less triangular in outline, with a larger apical angle and fewer ribs. A. similis,
Goldfuss,’ belongs to the same group, but is more rounded in outline, and has more
numerous ribs than A. subcostata.

Forbes states that English examples of this species were identified by d’Orbigny
as A. numismalis, VOrbigny,? but adds that they resemble much more nearly
VOrbigny’s A. striato-costata. They differ from the figures of A. numismalis given
by @Orbigny in being less triangular, and in having the posterior end more
truncated ; also the ribs are Jess numerous but more prominent, and form a larger
angle with the postero-dorsal margin. English examples were also seen by Pictet and
Renevier, and were identified by them with Astarte laticosta, Deshayes (= striato-
costata and subcostata, VOrbigny). The specimen figured by d’Orbigny is more
elongate than most of the English examples, but agrees in this respect with some
found in the Atherfield Clay of Sevenoaks. The specimens figured by Leymerie
are much larger than the English examples, and the ribs are more numerous and
less prominent. Some of the differences seen in the figures of the authors quoted in
the synonymy are probably due to the differences in the age of the specimens. In
the young specimens the posterior end is more rounded, in old specimens it is
more truncated.

Remarks.—Specimens which occur in the Crackers of Atherfield (Plate XV, figs.
1, 2) differ shghtly from those described above, but probably constitute only a local
variety ; the valves are not quite so convex, the ribs are rather more numerous and

' For figures and references see Holzapfel, ‘Die Mollusk. Aachen. Kreide’ (Paleontographica, vol.

xxxv, 1889), p. 194, pl. xix, figs. 1I—15. A. similis was referred to the genus Gouldia by Stoliczka :
Holzapfel discusses this subject, and I am in agreement with his conclusions.

9

* Pal. Frang. Terr. Crét.,’ vol. iii (1844), p. 63, pl. celxii, figs. 46; Pictet and Campiche, ‘Terr.
Crét, Ste, Croix’ (1866), p. 309,

ASTARTHR. 111

less prominent, and the posterior end of the shell is rather more pointed. This
form resembles A. angulata, Guéranger.!

Types.—The types of A. laticosta came from the Neocomian of Chaource and
Jully (Aube). D’Orbigny’s specimens of A. striato-costata were obtained from the
Neocomian of Marolles (Aube), Attancourt (Haute-Marne), and Saint-Sauveur
(Yonne). The specimens described by Forbes are in the Museum of the Geological
Society (No. 2181).

Distribution.— Atherfield Beds of Peasmarsh and Sevenoaks. Perna-bed of East
Shalford, and probably Atherfield. Recorded by Topley from the Atherfield Beds
of Haslemere, and the Hythe Beds of Lympne.

Astarte, sp. Plate XV, figs. 3, 4.

Some specimens from the Folkestone Beds of Folkestone are very similar
to A. subcostata, d’Orbigny, but are larger, less elongate, and have a smaller
apical angle.

AstTarTE OMALIOIDES, sp. nov. [ex Gurducr MS.]. Plate XV, figs. 5-7.

Description—Shell small, triangular or sub-quadrate, compressed, slightly
inequilateral, height and length nearly equal. Dorsal half of valves pointed.
Antero-dorsal margin slightly concave; postero-dorsal margin rather longer and
nearly straight, the remaining margin forming a regular curve. Umbones pointed.
Margins of valves finely crenulate.

Ornamentation consists of a few (usually 6 or 7) prominent, sharp, concentric
ribs, with steep dorsal slopes and more gentle ventral slopes. Interspaces very
broad. The ribs become more distant from one another in passing from the umbo
to the ventral margin. A few very faint concentric ribs are sometimes present also.

Measurements :

(1) (2) (3)
Length ; 50 E Ay 25 2 t-O mm.
Height ; 7 hy 425 40 ,,

(1—3) Gault, Folkestone.

Affinities. —This species is closely allied to A. subcostata (see p. 109), but is
relatively shorter and less convex, and has a smaller apical angle and rather fewer
ribs.

>

1 «Album Paléont. de la Sarthe’ (1867), p. 13, pl. xvi, fig. 5.

112 CRETACEOUS LAMELLIBRANCHIA.

Remarks.—Since the name Omalioides has been used in stratigraphical lists,’ it
seems desirable to retain it, although its construction is not in accordance with the
recommendations of the International Congress of Zoology.

Distribution.—Gault (zones vu, x, and xi) of Folkestone.

Asvarte rormosa, Sowerby, 1836. Plate XV, figs. 8-13.

1836. Asrarte rormosa, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv., pp.
239, 341, pl. xvi, fig. 16.

1842. — — F. Rimer. De Astartarum Genere, p. 21.

1850. — — A. ad Orbigny. Prodr. de Pal., vol. ii, p. 160.

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 186.

1871. — — F. Stoliczka. Paleont. Indica, Cret. Fauna 8S. India, vol.

ili, p. 285 (¢ Gouldia).

Non 1842. — — H. B. Geinitz. Char. d. Schicht. u. Petref. des sachs.-
bohm. Kreidegeb., pt. 3, p. 76, pl. xxi,
fig. 19 (see Geinitz, Elbthalgeb. i, p.
227).
1844. — — A,dOrbigny. Pal. Frang. Terr. Crét., vol. iii, p. 65, pl.
celxii, figs. 10—12 (A. subformosa,
d’Orb., 1850).

Description.—Shell small, rather convex, sub-triangular, moderately inequilateral.
Antero-dorsal margin slightly concave. Anterior and ventral margins forming a
regular curve. Posterior margin less curved, often truncated, and forming an
obtuse angle with the long and slightly convex postero-dorsal margin. Umbones
pointed. Lunule large, ovate, depressed, smooth, with a sharp border. Escutcheon
long, lanceolate, depressed, smooth, with a sharp border. Margins of valves smooth.

Ornamentation consists of strong concentric ribs with sharp summits, separated
by broad concave interspaces. The ribs end abruptly at the margins of the lunule
and escutcheon. On the ribs and interspaces fine concentric ridges may be seen.

Measurements :

(1) (2) (3) (4) (5) (6)

Length , 0 . 470°. 45 2 AOS 8 258 vo Oanme

Height » AND 2 AO. ANOS oomenao Oana O
(1—6) Blackdown.

33

Affinities. —A. formosa is smaller and has more numerous ribs than A. subformosa,

1 Price, ‘The Gault’ (1879), p. 58; Jukes-Browne, ‘ Cret. Rocks of Britain,’ vol. i (1900), p. 465.

ASTARTE. 113

@VOrbigny.! dA. acuta, Reuss,’ is another allied form, but possesses fewer ribs than
A. formosa. See also A. subcostata (p. 109).

Type.—From Blackdown, in the Bristol Museum.

Distribution.—Upper Greensand (zone of Schlenbachia rostrata) of Blackdown
and Haldon.

ASTARTE IMPOLITA, Sowerby, 1836. Plate XV, fig. 14.

1836. AsrarrE impouita, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp. 239, 341, pl. xvi, fig. 18.
1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 187.

The only example of this which I have seen is the type specimen from the
Greensand of Blackdown.’ Both valves are present, but the parts near the umbo
and lunule are missing. The specimen is in the Bristol Museum.

Sub-genus—Enriruyta, W. M. Gabb, 1864.

(‘ Geol. Surv. California, Paleont.,’ vol. i, p. 180. Stoliczka, ‘ Paleont. Indica, Cret. Fauna, 8. India,’
vol. ii, 1870, p. 156.)

Asrarre (ErtpHyta) opovata, Sowerby, 1822. Plate XV, figs. 15-18. Plate XVI,

ia
figs. 1-3.

1822. AsrartEe opovara, J. de CO. Sowerby. Min. Conch., vol. iv, p. 73, pl. cecliii.

1842. — — F. Rimer. De Astartarum Genere, p. 22.
1845. —- E. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 241.

1850. Corsis onovara, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 78.
1852. Asrarre Brunner, F. J. Pictet and W. Roux. Moll. Foss. Gres verts de
Gentve, p. 435, pl. xxxii, fig. 3.
=e — aurarris, Pictet and Rous. Ibid., p. 436, pl. xxxiii, fig. 1.
1854. — osovata, J. Morris. Cat. Brit. Foss., ed. 2, p. 187.
1857. — — F. J. Pictet and E. Renevier. Foss. Terr. Aptien (Mater.
Pal. Suisse, ser. 1), p. 86, pl. xi, fig. 1.

1 «Prodr. de Pal.,’ vol. ii (1850), p. 77.

2 «Die Verstein. der béhm. Kreideformat.,’ pt. 2 (1846), p. 3, pl. xxxiii, fig. 17; pl. xxxvii, fig. 14;
Notling, ‘Die Fauna d. baltisch. Cenoman.’ (Paleont. Abhandl., vol. ii, 1885), p. 28, pl. v, fig. 1
According to Nétling, A. plauensis, Geinitz, is a synonym of A. acuta.

3 Astarte multistriata was also described by J. de C. Sowerby from Blackdown, but I have not
seen any example of it. See ‘Trans. Geol. Soe.,’ ser. 2, vol. iv, pp. 240, 341, pl. xvi, fig. 17 ; Morris,
“Cat. Brit. Foss.,’ ed. 2 (1854), p. 187.

15

114 CRETACEOUS LAMELLIBRANCHIA.

21865. Asrarte opovata, H. Coquand. Mon. Aptien de l’Espagne, p. 122,
pl. xii, figs. 3, 4.

1866. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Mateér. Pal. Suisse, ser. 4), p. 312.

1871. = os (Erypuyta), F. Stoliczka, Palwont. Indica, Cret. Fauna,
8. India, vol. iii, p. 285.

1892. _ — O. Behrendsen. Zeitschr. d. deutsch. geol. Gesellsch.,

vol. xliv, p. 22.

Description.—Shell large, oval, transverse, moderately inflated, very imequi-
lateral. Anterior margin rounded, concave in front of the umbo. Behind the
umbo the dorsal margin has a gentle and regular curve. Posterior margin rounded
or sub-truncate. Umbones prominent, curving forward. Lunule deep. Escutcheon
narrow, deep.

Ornamentation consists of numerous, strong, close, somewhat irregular concentric
ribs, on which fine, concentric, linear ribs occur.

Measurements :

(1) (2) (3) (4) (5) (6)
Length . LUD TAR whe is POE Par aioe ame rriins
Height . 162% 258) 35 60, fe 59" eos 59 ,,

(1-4) Perna-bed, Atherfield.
(5,6) Perna-bed, Sandown.

Affinities —Astarte Beaumonti, Leymerie,' and A. transversa, Leymerie,* are
closely allied to A. obovata, and were regarded by Forbes as merely varieties of the
latter. Pictet and Renevier (1857) were inclined to regard the differences as not
of specific importance. Pictet and Campiche (1866), however, kept the three forms
distinct, but were uncertain whether they should be regarded as species or varieties.
They state that in A. Beaumonti the margin is smooth, whilst in A. obovata and
A. transversa it is crenulated. In the first two forms the posterior margin is more
rounded, but in the last it is more truncate. It is very doubtful whether the
crenulation of the margin is a feature of specific importance in Asfarte; imdeed,
one writer® thinks that it is a characteristic of sex. Whether the other differences
are of specific value can be determined only by the comparison of a number of
examples of A. Beawmonti and A. transversa with specimens of A. obovata.

1 «Mem. Soc. géol. de France,’ vol. v (1842), pp. 4, 24, pl. iv. fig. 1. D’Orbigny, ‘Terr. Crét.,’
vol. iii (1844), p. 60, pl. celx. Pictet and Campiche, ‘Terr. Crét. Ste. Croix’ (1866), p. 300, pl. exxiv,
fig. 1. Wollemann, ‘ Biv. u. Gastrop. d. deutsch. u. hollind. Neocoms’ (1900), p. 95.

2 Op. cit. (1842), pp. 4, 24, pl. v, fig. 5. D’Orbigny, op. cit., p. 61, pl. celxi. Pictet and Campiche,
op. cit., p. 301, pl. exxiv, fig. 2. De Loriol, ‘Anim. Invert. Foss. Mt. Saléve’ (1861), p. 68,
pl. vin, fig. 9.

3 A. Ostrooumoff, ‘Zool. Anzeiger,’ vol. xxiii (1900), p. 499.

ASTARTE. Ls

The shallow pallial smus shown in internal casts, and the characters of the hinge
seem to warrant the reference of this species to the sub-genus Hriphyla.

Remarks.—Some of the specimens found in the Isle of Wight have the posterior
end rounded, but in the larger number it is more or less distinctly truncated. The
former approach A. Beawmonti; the latter resemble A. transversa. I have not seen
any examples from the Isle of Wight which show the internal margin of the valve
sufficiently clearly to determine whether it is crenulate or not, but in an internal
cast from the Hythe Beds of Hythe (Museum of the Geological Society, No. 2187)
the crenulation is distinct.

The specimens of A. obovata show a fairly large amount of variation. In some
the anterior part of the valve is quite short, as in Leymerie’s figure of A. trans-
versa; in others it is much longer. The relative height and length, the amount
of rounding or truncation of the posterior margin, and the coarseness of the
ornamentation also vary.

The specimens from the Hythe Beds of Hythe are very poorly preserved.
Those from the Greensand of Blackdown and Haldon appear, so far as one can tell
from the few perfect specimens available, to be rather shorter than most of the
Lower Greensand examples.

Types.—The type cannot be found ; it came from the Perna-bed of Sandown.

Distribution.—Lower Greensand (Perna-bed) of Atherfield and Sandown.
Recorded by Topley from the Atherfield Beds of Peasemarsh and Shalford, and
from the Hythe Beds of Hythe and Lympne.

Upper Greensand (zone of Schlenbachia rostrata) of Blackdown and Haldon.

Astarte (Eripayia) Lavis (Phillips), 1829. Plate XVI, figs. 5-7. Plate XVII,
fie. 1,

1829. Crassrna Leavis, J. Phillips. Geol. Yorks., p. 122, pl. ii, fig. 19 (? fig. 18).
1835. AsTarTE Lmvis, Phillips. Ibid., ed. 2, pt. 1, p. 158 (ed. 3, 1879, p. 252).
1854. — — J.Morris. Cat. Brit. Foss., ed. 2, p. 187.

Description.—Shell large, thick, convex, ovate, usually considerably inequilateral;
height and length nearly equal, or the height may be rather greater than the length
or vice versd. Antero-dorsal margin rather long and slightly concave; postero-
dorsal margin very long and moderately convex. Anterior and ventral margins
well rounded. Posterior extremity rounded or sometimes subangular. Umbones
large. Lunule large, ovate, deep, nearly smooth, with a sharp border. Escutcheon
narrow, deep.

116 CRETACEOUS LAMELLIBRANCHIA.

Ornamentation consists of numerous, rather strong, narrow, concentric ribs
which are somewhat irregular.

Hinge-plate broad, triangular. In the left valve two strong cardinal teeth and
one lateral at the margin of the lunule. Teeth of right valve not seen. Margins
of valves strongly crenulate.

Measurements :

a) (2) (3) (4)
Length 2 57 : 51 : 51 : 44. mm.
Height 59 ; 56 3 47 i B39 5

(1-4) Claxby Ironstone, Benniworth Haven,

Affinities. —This species is allied to Astarte Semanni, de Loriol,' of which good
specimens are found in the Portland Sands of Swindon. In some cases the resem-
blance is very close, but generally the umbones are more prominent, the antero-
dorsal margin relatively longer, and the valves more convex in A. /evis than in
A, Semanni.

A. Buchi, Romer,’ is apparently allied to A. levis, but is distinguished by the
greater anterior curvature of its umbones. A. gigantea, Leymerie,’ is less inequi-
lateral and more elongate than A. levis.

Remarks.—Most of the examples of this species have been obtained from the
Claxby Ironstone. Only two have been seen from the Speeton Clay, one being in
the Leckenby Collection (Sedgwick Museum), the other in Mr. Lamplugh’s Col-
lection; these appear to agree with the larger example of Astarte levis figured by
Phillips (fig. 19).

Types.—The type, from the Speeton Clay, appears to be missing.

Distribution.—Claxby Ironstone (zone of Belemnites lateralis) of Benniworth
Haven. Speeton Clay of Speeton.

Astarte (Eripuyna) strata, Sowerby, 1826. Plate XVII, figs. 2-7.

1826. Asrarre srriava, J. de C. Sowerby. Min. Conch., vol. vi., p. 35, pl. dxx,

fig. 1.
1836. — conctnna, J. de C. Sowerby. Trans. Geol. Soe., ser. 2, vol. iv,
pp. 239, 341, pl. xvi, fig. 15.

1842. — — F. Rimer. De Astartarum Genere, p. 21.

1 De Loriol and Pellat, ‘Portlandien de Boulogne-sur-mer’ (1866), p. 68, pl. vi, fig. 9. E. G.
Skeat and V. Madsen, ‘ Jur. Neoc. and Gault Boulders in Denmark’ (1898), p. 123, pl. iii, fig. 2.

2 «De Astartarum Genere’ (1842), p. 20, fig. 4. Pictet and Renevier, ‘Foss. Terr. Aptien’ (1856),
p. 85, pl. x, fig. 1.

3 For references see Pictet and Campiche, ‘Terr. Crét. Ste. Croix’ (1866), p. 298,

ASTARTE. U8 i

1850. Asrarte srriara, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 160 (partim).
a _- concinna, @Orbigny. Tbid., p. 160.

1854. — striata, J. Morris. Cat. Brit. Foss., ed. 2, p. 187.
— — conctnna, Morris. Ibid., p. 186.
1866. — striaTa, I’, J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4), p. 230.
1871. — — (Erypurua), F. Stoliczka. Paleont. Indica, Cret. Fauna

8. India, vol. iii, p. 285.
— — CONCINNA (HEripuyna), Stoliczka. Ibid., p. 285.
2? 1873. Eripnynia srriata, H. B. Geinitz, Das Elbthalgeb. in Sachsen (Paleon-
tographica, vol. xx, pt. 1), p. 228,

pl. li, figs. 1-3.

Deseription.—Shell with rounded outline, sometimes nearly orbicular, usually
only moderately inequilateral, moderately convex. Length usually a little greater
than height, but occasionally less. The margin in front of the umbo is concave
for a short distance ; behind the umbo it is convex; the anterior, the ventral, and
posterior margins form a more or less regular curve. Umbones rather small,
placed a little in front of the median line. Lunule small, deep, with a sharp edge.
Escutcheon narrow.

Ornamentation consists of numerous small concentric ribs, which are slightly
irregular and are separated by linear grooves; at intervals somewhat deeper
grooves may occur.

Hinge-plate wide. Two cardinal teeth in each valve, and one lateral tooth
next the lunule in the left valve. _Adductor impressions deep, the anterior some-
what elongated. Pallial sinus shallow, rounded. Margins of valves smooth.

Measwrements :
(1) (2) (3) 4) (5) (6) (7) (8)
Length . 46 . 45 . 44 . 42 . 39 . 37 . 85 . 28 mm.
Height . 45 . 42 . 41 . 43 . 37 . 84 . 3845. 275 ,,
(1-8) Blackdown.

Affinities. —This species is closely allied to A. (Hriphyla) lenticularis (Goldfuss),'
but the outline of the valve is less regularly orbicular.

Astarte Konincki, @ Archiac,? from the Tourtia of Tournay, was regarded by
d’Orbigny, Pictet and Campiche, Stoliczka, and Geinitz as a synonym of A. striata.
I have not seen any example of the former, but it appears to differ from A. striata
in having less prominent umbones, more inflated valves, a more regularly orbicular

1 «Petref. Germ.,’ vol. ii (1840), p. 228, pl. exlvi, fig. 16. Holzapfel, ‘ Zeitschr. d. deutsch. geol.
Gesellsch.,’ vol. xxxvi (1884), p. 458, pl. vi, figs. 1, 2, and ‘ Palwontographica,’ vol. xxxv (1889),
p. 195, pl. xiv, figs. 5-7.

2 «Mém, Soe. géol. de France,’ ser 2, vol. ii (1847), p. 302, pl. xiv, fig. 4.

118 CRETACEOUS LAMELLIBRANCHIA.

outline, and apparently also fewer ribs. ‘’wo imperfect specimens from the
Cenomanian (Bed 11) of Dunscombe were referred to A. Konincki by the late
C. J. A. Meyer, but they are less convex than that species and seem to agree
more nearly with A. striata.

Astarte concinna, Sowerby, was regarded by Stoliczka as probably identical with
A, striata. It is known by the type specimen only, and agrees with A. striata,
except that it is rather higher and more inequilateral. I believe that it is merely
an individual variation of A. striata.

T'ypes.—From Blackdown, in the British Museum. The type of A. coneinna is
from Blackdown and is now in the Bristol Museum.

Distribution —Upper Greensand (zone of Schlanbachia rostrata) of Blackdown.

Genus—Oris, M. J. L. Defrance, 1825.

(‘ Dict. Sci. nat.’ vol. xxxvi, p. 219.)

Oris nrocomiensts, d’Orbigny, 1844. Plate XVII, figs. 8-12.

1842. Opis A. Leymerie. Mém. Soc. géol. de France, ser. 2, vol. v,
p. 25, pl. vii, fig. 4.

1844. — wexocomtensis, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 51,
pl. ecliu, figs. 1—5.

1850. — -- d’Orbigny. Prodr. de Pal., vol. ii, p. 76.

8559. — — G. Cotteau. Moll. Foss. de l’Yonne, p. 67.

1857. — — FJ. Pictet and E. Renevier. Foss. Terr. Aptien (Matér.

Pal. Suisse, ser. 1), p.
83, pl. ix, fig. 7.

1861. — Dersort, P. de Loriol. Anim. Invert. Foss. Mt. Saltve, p. 66, pl. viii,
figs. 4—7.
1866. — wnexocomiensis, I’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse, ser. 4),
p. 324, pl. exxv, figs. 3, 4.

1868. — = P. de Loriol. Valangien d’Arzier, p. 31.
21871, — - W. A. Ooster. Protozoe Helvet., vol. ii, p. 101, pl. xv,
fig. 17.
1883. — — W. Keeping. Foss. ete., Neoc. Upware and Brickhill,
p. 121, pl. vi, fig. 8.
1900. — — A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.

holliind. Neocoms (Abhandl. d. k.
preussisch. geol. Land., N. F., pt.
31), p. 102.

Description—Shell trigonal or sub-quadrilateral, much higher than long,
inequilateral, greatly inflated, but with flattened sides. Anterior margin rounded,

OPIS. 119

Posterior margin truncated, slightly concave, forming an angle with the gently
curved ventral margin and also with the postero-dorsal margin. Umbones
prominent, slender, greatly incurved, almost touching in the young, but separated
in older specimens. A prominent carina extends from the umbo to the postero-
ventral angle, cutting off an area which is divided into two parts by a prominent
but rounded carina which ends at the postero-dorsal angle; the outer part only of
the area is seen in a side view, and is concave ; the inner part is depressed, and its
dorsal portion is flattened and resembles a lunule. Lunule very large, cordate,
flattened.

Ornamentation consists of many small concentric ribs separated by narrow
grooves. Behind and in front of the flattened part of the valve this ornamentation
becomes less distinct or may disappear altogether. Margin of valve entire.

Measurements :

(1) (2) (3) (+) (5)
Length ee 22 2070 Ge ee 4 om.
Height’ is) 35 DOs ee G20 ote ee LO er
Thickness . 26 26 2A. tie age Aes

(1—5) Lower Greensand, Upware.

Affinities —This species shows some resemblance to O. Hugardiana, VOrbigny,”
from the Gault.

Remarks.—The shell is relatively higher in large than in small specimens. In
all the examples obtained from Upware the shell is preserved. Specimens from
Seend are in the Museum of Practical Geology.

Types.—Leymerie’s specimen came from the Lower Neocomian of Bernon
(Aube). D’Orbigny’s specimens were obtained from Saint Sauveur (Yonne),
Bernon, and Marolles. ‘he specimen figured by Keeping is in the Sedgwick
Museum.

Distribution—Lower Greensand of Upware and Seend. Internal casts,
probably belonging to this species, are found in the Lower Greensand of Coleshill
near Faringdon.

OPIS HALDONENSIS, sp. nov. Plate XVIII, fig. 1 a-d.

Description —Shell trigonal, higher than long, moderately inequilateral, convex,

with flattened sides. Anterior margin slightly convex, passing gradually into the

! Measured from the umbo to the postero-ventral angle.
2 Syn. O. Sabaudiana, dOrbigny, ‘Pal. Frane. Terr. Crét.,’ vol. iii (1844), p. 53, pl. celvii, figs.
4—6; Pictet and Roux, ‘ Moll. Foss. Gris verts de Gentve’ (1852), pp. 432—454, pl. xxxii, fig. 1.

120 CRETACEOUS LAMELLIBRANCHIA.

slightly curved ventral margin. Posterior margin somewhat oblique, slightly
concave. Postero-ventral angle rounded. Umbones high, prominent, not much
incurved. A prominent, rounded carina extends from the umbo to the postero-
ventral angle, and cuts off a posterior area which is divided into two parts by a
strong, rounded carina ending at the postero-dorsal angle. The part of the area
between the carine is concave; the part behind the median carina is deeply
depressed. Lunule large, very deep, flattened. Surface of shell apparently
smooth. Length, 45 mm. Height, 58 mm.

Affinities —It is possible that this species may be related to O. Galliennei,
d@’Orbigny,! which seems to be known by casts only, but the height of the shell
appears to be relatively less. O. Calliennei has been identified by some authors
with O. bicornis (Geinitz)* from the Cenomanian of Plauen. The latter differs
from the species described above in possessing strong concentric ribs and in the
absence of a carina between the umbo and the postero-ventral angle.

Remarks.—The only undoubted example of this species which I have seen is a
right valve collected by the late W. Vicary, and now in the British Museum. ‘The
surface of the shell is not weli preserved, but appears to have been nearly smooth.

An imperfect specimen of a large Opis (length about 63 mm.) from the
Chloritic Marl of Eggerdon Hill (Dorset) is in the Sedgwick Museum, Cambridge,
and may belong to this species.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Haldon.

Oris, Sp. PLOVil, fies. 13 a-c, 14a-c.

Description —Shell small, sub-triangular, rather oblique; greatest convexity
along the carina. Anterior margin rounded; posterior margin slightly convex.
Umbones prominent, sharp, considerably curved anteriorly. Carina sharp,
prominent, cutting off a steeply sloping posterior area, which is not divided by a
median carina. Sides of shell flattened, sloping slightly in front of the carima, and
passing gradually into the anterior part of the shell. Lunule very deep, with a
sharp border.

Ornamentation consists of regular, concentric ribs. Posterior area nearly
smooth.

1 «Pal. Franc. Terr. Crét.,’ vol. iii (1844), pl. eclviibis, fig. 5 (mot described in the text) ;
Guéranger, ‘ Album Paléont. de la Sarthe ’ (1867), p. 17, pl. xxii, fig. 13.

2 “Das Elbthalgeb. in Sachsen” (‘ Palzeontographica,’ vol. xx, pt. 1, 1873), p. 227, pl. 1, figs. 1—3.
Internal casts of Opis from the base of the Chalk at Maiden Newton and Chard have been recorded
as O. bicornis? (Gein.) by Jukes-Browne, ‘Cret. Rocks of Britain,’ vol. ii (1903), pp. 118, 122. Two
of the specimens on which the determination was based are in the Oxford Museum.

CARDITA. 121
Measurements :
(1) (2)
Length : : : 8 75 mm
Umbo to postero-ventral angle 12 : LIOR:

(1, 2) Haldon.
Affinities —This species may perhaps be related to O. cenomanensis, Guéranger, |
but the figure of the latter is too indistinct for recognition.

Remarks.—There are four examples of this species in the Vicary Collection,

British Museum.
Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Haldon.

Family—CARDITIDA, Gill.

Genus-—Caxrpita, J. G. Bruguiére, 1792.’
(‘ Encye. méth., Vers,’ vol. i, p. 401.)

Carpita ? FENESTRATA (Forbes), 1845. Plate XVIII, figs. 2-4.

1845. Venus? renesrrata, HZ. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 240,

pl. ii, fig. 6.
1850. Carpira — A. d’Orbigny. Prody. de Pal., vol. ui, p. 77.
1854. VeENus = J. Morris. Cat. Brit. Foss., ed. 2, p. 230.
1856. Carpira — F. J. Pictet and E. Renevier. Foss. Terr. Aptien

(Matér. Pal. Suisse, ser. 1), p. 82,
pl. ix, fig. 4.

1866. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p. 333.

1871. -- _ F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,

vol. iii, p. 287.

Description —Shell oval or somewhat rhomboidal, much longer than high, very
inequilateral, moderately inflated, but with flattened sides. Anterior margin
rounded; ventral margin slightly curved or almost straight, and nearly parallel
with the dorsal margin; posterior margin obliquely truncated, forming an acute angle

1 « Album Paléont. de la Sarthe’ (1867), p. 13, pl. xvi, fig. 3.
2 Owing to the difficulty of distinguishing the fossil forms of Cardita from Venericardia when, as
in the case of nearly all the examples found in the Cretaceous rocks of England, the hinge is unknown,

all the species are, for the present, referred to Cardita.
16

122 CRETACEOUS LAMELLIBRANCHIA.

with the ventral margin, and an obtuse angle with the dorsal margin. Umbones
moderately prominent, curving forwards, bearing a carina which extends to the
postero-ventral angle and cuts off a flattened or concave area. Lunule ovate,
rather large, nearly smooth. Escutcheon with a sharp edge.

Ornamentation consists of narrow, rounded, radial ribs, separated by broad,
flat interspaces, and crossed at rather distant intervals by strong, narrow, con-
centric, lamellar ribs, which give rise to a scale-like projection where they join
the radial ribs. The postero-dorsal area has similar concentric ribs, and a strong
radial rib near the dorsal margin, and another near the middle of the area with
smaller ribs between.

Measurements :
(1) (2) (3) (4) (5) (6)
Length 20 Ls) 19 19 18 16 mm.

Height 14. 13 12 115 12 ih aes
(1—6) Perna-bed, Atherfield.

Affinities—C. fenestrata appears to be quite distinct from other Cretaceous
species of Cardita, but shows some resemblance in form to U. tricarinata, d’Orbigny,
from the Cenomanian of Le Mans. The hinge and interior are unknown, and the
generic position of the species is not free from doubt. Stoliczka remarks
that ‘OC. fenestrata is not unlike a Venerupis.’

Type-—From Peasmarsh, in the Museum of the Geological Society, Nos.
9182, 2183.

Distribution—Perna-bed and Atherfield Clay of Atherfield. Atherfield Beds
of Peasmarsh and Hast Shalford.

CARDITA UPWARENSIS, sp. nov. Plate XVIII, fig. 5.

1883. Carprra rotunDaTA? W. Keeping. Foss., etc. Neoc. Upware and Brick-
hill, p. 121, pl. vi, fig. 7.

Description.—Shell subtriangular, inflated, height and length nearly equal,
inequilateral. Anterior margin rounded, passing. gradually into the convex ventral
margin. Posterior margin truncated, oblique, not sharply limited from the postero-
dorsal margin. Umbones prominent, strongly curved anteriorly, with a rounded

1 «Pal. Frane. Terr. Crét.,’ vol. iii (1844), p. 95, pl. cclxxxiii bis., figs. 5—7; Guéranger, ‘ Album
Paléont. de la Sarthe’ (1867), p. 13, pl. xvi, figs. 19, 20.

CARDITA. 123

carina extending to the postero-ventral angle, and cutting off a steeply-sloping
postero-dorsal part of the valve. Lunule rather small, cordate, broader than long.,

Ornamentation consists of about twenty-five radial ribs on the part of the valve
in front of the carina; the ribs are strong and rounded, but are narrower than
the interspaces. Both are crossed by regular concentric lamellae, which become
prominent on the ribs. On the postero-dorsal area the ribs are smaller, more
numerous, and closer together; two of these ribs are rather stronger than the
others, and divide the area into three parts. Leneth 21 mm.; height 20°5 mm.;
thickness 17 mm.

Affinities —This species was doubtfully referred by W. Keeping to C. rutundata,
Pictet and Roux, but it differs from that form by its fewer and stronger ribs and
more triangular outline (see p. 125).

In form it resembles C. Dupiniana, d’Orbigny,' but the ribs on the postero-
dorsal area are smaller and more numerous. In this respect, and in its shorter
and less quadrate outline, it differs from C. neocomiensis, d’ Orbigny.”

Remarks.—I have seen only three examples of this species, two of which are in
the Sedgwick Museum, and one is in the collection of Mr. J. F. Walker.

Distribution.—Lower Greensand of Upware and Potton.

Carprra, sp. Plate XVIII, fig. 6.

A specimen consisting of the united valves from which the ventral parts are
missing was obtained by Leckenby from the Peria-bed of Atherfield, and is now
in the Sedgwick Museum. It shows some resemblance to C. upwarensis (see
above), but is more elongate and more distinctly carinate.

CarpIva, sp.

T'wo specimens of Cardita from the Hythe Beds of Maidstone are in the Museum
of the Geological Society. They were examined by Edward Forbes,’ who identified
one with C. neocomiensis, d’Orbigny, and the other with C. quadrata, d’Orbigny.
The specimens are similar in form to those species, but their state of preservation
is too imperfect for satisfactory determination.

1 «Pal. Franc. Terr. Crét., vol. iii (1844), p. 88, pl. eelxviii, figs. 6—10; Pictet and Campiche,
‘Foss. Terr, Crét. Ste. Croix’ (‘Matér. Pal. Suisse,’ ser. 4, 1866), p. 334, pl. exxvi, figs. 4, 5.

2 D’Orbigny, op. cit., p. 85, pl. celxvii, figs. 1—6.

3 «Quart. Journ. Geol. Soc.,’ vol. i (1845), p. 242.

124

CarpITA TENUIVOSTA (Sowerby), 1836.

1836.

1838.
1842.
1844.
1846.

1850.
1854.
1855.
1866.

1871.

Non 1842.

— 1846.

— 1873.

— 1885.

— 1889.

CRETACEOUS LAMELLIBRANCHIA.

Plate XVIII, figs. 7-14.

VENERICARDIA TENUICOsTA. J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol.

iv, pp. 114, 259, 356, pl. xi,
Lievens

Carpium TETRAGONUM, H. Michelin. Mém. Soc. géol. de France, vol. iii, p.

102, pl. xii, fig. 3.

VENERICARDIA TENUICOSTA, A. Leymerie. Mem. Soe. géol. de France, ser. 2,

vol. v, p. 25, pl. ii, fig. 9.

Carpira Tenvurcosta, A. d’Orbigny. Pal. France. Terr. Crét., vol. ili, p. 87,

pl. celxviii, figs. 1—5.

VENERICARDIA TENUICOsTA, A. Leymerie. Statist. géol. et min. de l’Aube,

CaRDITA

VENERICARDIA

pl. v, fig. 7.

@ Orbigny. Prodr. de Pal., vol. ii, p. 137.

J. Morris. Cat. Brit. Foss., ed. 2, p. 191.

G. Cotteau. Moll. Foss. de 1’Yonne, p. 72.

F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal. Suisse,
ser. 4), p. 335, pl. exxvi, figs.
6—9.

F. Stoliczka. Paleont. Indica, Cret. Fauna 8.
India, vol. iii, p. 287.

H. B. Geinitz. Char. d. Schicht. u. Petref. des
siichs.-bdhm. Kreidegeb., pt.
3; ps 40) pl xx, ahem ona:
Geinitzi, VOrbigny).

Carpita (VENERICARDIA) TENUICOosTA, A. H. Reuss. Die Verstein. der bohm.

Kreideformat., pt. 2, p. 4, pl.
xxxili, fig. 16 (C. corrugata,
Reuss).

Carpira Tenutcosta, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleon-

tographica, vol. xx, pt. 2), p. 60,
pl. xvii, figs. 11—13.

— (Venericarpia) TENuIcosta, F. Nitling. Die Fauna d. baltisch.

Cenoman. (Paleont. Abhandl., vol.
ii), p. 29, pl. v, fig. 4.

— renurcosra, A. Fritsch. Stud. im Gebiete der bohm. Kreide-

format., iv. Teplitz. Schicht., p. 78,
fig. 62.

Fritsch. Tbid v. Priesener Schicht., p. 91.
A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.

holliind. Neocoms (Abhandl. d.
k. preussisch. geol. Land., N. F.,
pt. 31), p. 94, pl. iv, fig. 9.

CARDITA. 125

Description.—Shell more or less sub-quadrate, rounded, moderately convex,
with the postero-dorsal portion compressed ; length greater than height ; moderately
inequilateral. Postero-dorsal margin only slightly curved; posterior margin more
or less truncated, passing by a regular curve into the ventral margin, which is only
slightly convex and nearly parallel with the postero-dorsal margin. Anterior
margin rounded. Antero-dorsal margin concave. Umbones curved anteriorly.
Lunule ovate, nearly smooth. Hscutcheon lanceolate, with a sharp edge.

Ornamentation consists of 47 to 57 rounded radial ribs, which are separated
by furrows of greater breadth than themselves; near the postero-dorsal margin
these ribs are rather closer together than elsewhere. In some cases the postero-
dorsal part of the valve is divided into two parts by two ribs, which are more
prominent than the others. At regular intervals concentric lamelle occur and form
marked projections where they cross the ribs. Near the umbo these lamellz are
more widely separated, and near the margin, especially in large specimens, they
are closer together than elsewhere. Sometimes faintly marked concentric ridges
may be seen on the ribs between the lamelle. Margins of valves crenulate.

Measurements :
(1) (2) (8) (4 (5) (6) (7) (8) (9) (Qo) (1) (2) (8) (14)
Length. 80 27 25 24 24 235 23 23 22 22 20 16 15 15 mm.

Height. 265 23 22 22 20 21 Py 19-5 20 V9 a Ab: 14) 1S ees
(1—14) Gault, Folkestone.

Affinities —This species has more numerous ribs and is less inflated than
C. neocomiensis, d’Orbigny and C. Dupiniana, @ Orbigny.' It possesses about the
same number of ribs as C. Constanti, @Orbigny,® but is less elongate and less
inflated. C. rotundata, Pictet and Roux,’ differs from OC. tenwicosta in beng
more inflated, and can be regarded as only an individual variation. Some examples
found at Folkestone, which in other respects agree with C. tenwicosta, are as much
inflated as the type of C. rotundata. C. clathrata, Buvignier,* is a small form, but
has the concentric laminz more widely separated than in even the young of
C. tenuicosta. O. argonnensis, Buvignier,’ is more compressed and has more slender
ribs than C. tenuicosta. O. cenomanensis, d’Orbigny,® is distinguished from
C. tenuicosta by its broader ribs and more closely placed concentric lamelle.

(. tenuicosta has narrower ribs and broader furrows than the forms from the Chalk

1 For references to figures of these species see p. 123, footnotes 1, 2.

2 «Pal. Franc. Terr. Crét.,’ vol. iii (1844), p. 89, pl. celxix, figs. l—5; Pictet and Campiche, * Poss
Terr. Crét. Ste. Croix’ (‘Matér. Pal. Suisse,’ ser. 4, 1866), p. 337, pl. exxvi, fig. 10.

3 «Moll. Foss. Grés verts de Gentve’ (1852), p. 443, pl. xxxiii, fig. 6.

4 ‘Statist. géol., etc., de la Meuse,’ Atlas (1852), p. 19, pl. xv, figs. 16, 17.

5 Tbid., p. 19, pl. xxxii, figs. 1—3.

6 D’Orbigny, op. cit., p. 94, pl. celxxxiii bis., figs. 1-4.

126 CRETACEOUS LAMELLIBRANCHIA.

of Saxony and Bohemia which have been referred to that species by Geimitz and
by Reuss. ©. tenwicosta of Reuss is the type of C. (Venericardia) bohemica,
Griepenkerl.!

Remarks.—Numerous specimens of C. tennicosta from Folkestone have been
examined, and they are found to show a considerable amount of variation in con-
vexity and in relative height and length.

Type.—The type came from the Gault of Folkestone, but cannot now be found.
Distribution—Gault (zones i, v, vii, vill, 1x, xi) of Folkestone. Recorded by
Jukes-Browne from the Cambridge Greensand, and by Barrois from the Upper

Greensand (zone of Schlenbachia rostrata) of the Isle of Wieht.

Carpiva Corranpina, d’ Orbigny, 1844. Plate XVIII, figs. 15, 16.

1844, Carprra Corranprna, A. d’Orbigny. Pal. France. Terr. Crét., vol. 11, p. 91,
: pl. cclxix, figs. 6—8.

1871. -— — F. Stoliczka. Paleont. Indica, Cret. Fauna §. India,
vol. iii, p. 287.
? 1895. -- ef. Corrauprna, H. Tiessen. Zeitschr. der deutsch. geol. Gesellsch.,

vol. xlvii, p. 485.

Remarks.—Examples of a species of Cardita, which is not uncommon in the
Chloritic Marl of Dorset, appear to belong to C. Cottaldina, but their state of
preservation is very unsatisfactory. Most of the specimens are internal casts, and
in cases where parts of the shell are present the surface is very imperfect, so that
the characters of the ornamentation cannot be clearly distinguished. M. Raoul
Fortin informs me that the preservation is equally unsatisfactory m the Cenomanian
of Rouen, from whence d’Orbigny’s specimens were obtained.

The shell is quadrate in outline, very convex, carinate, and somewhat longer
than high. The ornamentation appears to consist of about 40 ribs, separated by
interspaces of great width.

OQ. Cottaldina may be distinguished from C. tenuicosta (p. 124) by its fewer ribs,
by the length and height being more nearly equal, and by the greater convexity of
the valves.

Measurements :

(a) (2) (3)
Length . : 21 . 20 : 16°5 mm.
Height . F 19 : 18 ; Ae
Thickness : 16 ; 5: eee Oe

(1—3) Chloritie Marl. (1) Chaldon, (2) Chard, (3) Balcombe.

1 * Paleeont, Abhandl.,’ vol. iv (1889), p. 58.

CARDITA. 12

i |

Distribution.—Chloritic Marl of Baleombe, Cerne, Chaldon, Chalmington, Chard,
Maiden Bradley, and Maiden Newton. Recorded by Jukes-Browne from the
Chloritic Marl and the zone of Schlanbachia varians of the Isle of Wight.

CarDITA, sp.

Specimens of Cardita from which the shell has disappeared, but showing traces
of the ribs, are found in the Chalk Marl of Ventnor, Folkestone, etc. These are
too imperfect for specific determination. A specimen from Ringmer was figured
by Sowerby,' and was subsequently regarded by d’Orbigny® as an example of his
C. dubia.

Somewhat similar specimens also occur in the Upper Greensand of Devizes.

Carpita cANcELLATA, Woods, 1897. Plate XVIII, figs. 17, 18.

1897. Carprra canceLtata, H. Woods. Quart. Journ. Geol. Soc., vol. liii, p. 390
pl. xxvii, figs. 2—5.

Description.—Shell oval, slightly imequilateral, inflated, postero-dorsal part
compressed, faintly carinate ; length rather greater than height; margins rounded.
Umbones moderately prominent, curved anteriorly.

Ornamentation consists of a large number of radial ribs separated by narrow
furrows, and crossed by numerous concentric ribs, giving a nodular appearance at
the points of intersection. The concentric ribs are more distinct on the anterior
part and the radial ribs more distinct on the median and posterior parts of the
shell. Margin of valves finely crenulate.

Measurements :
(1) (2) (8)
Length ; 18 F 16 : 13 mm.
Height 5 16 ; Nala Lhe

(1—3) Chalk Rock, Cuckhamsley.

Affinities —This species is more inflated and more rounded than C. fenwicosta
(p. 124), and possesses more numerous radial ribs with narrow furrows and
strong concentric ribs instead of lamine.

The concentric ribs distinguish OC. cancellata from the forms described by

1 ¢Min. Conch.,’ vol. iii (1820), p. 106, pl. cclix, fig. 3 (the original is now in the British Museum).
Venericardia ? Mantell, ‘ Foss. 8. Downs’ (1822), p. 126.

2 «Pal. Franc. Terr. Crét.,’ vol. iii (1844), p. 92, pl. celxx, figs. 1—5. Gucranger, ‘ Album
Paléont. de la Sarthe’ (1867), p. 13, pl. xvi, figs. 14—18.

128 CRETACEOUS LAMELLIBRANCHIA.

Geinitz! and by Reuss” as C. tenuicosta. The concentric ribs and the nodular
character which they give to the radial ribs separate C. cancellata from Venericardia
santonensis, Miiller.®

Remarks.—The specimens of C. cancellata are chiefly in the form of internal
and external moulds ; wax casts of the latter show the character of the ornamenta-
tion. In a few cases small portions of the shell are still preserved.

T'ype—From the Chalk Rock of Cuckhamsley, in the Sedgwick Museum.

Distribution —Chalk Rock of Cuckhamsley, Aston Hill, Chinnor Hill, Thick-
thorn Hill (Bledlow), Boxmoor, Luton, and Wood Ditton.

Family—CRASSATELLITIDA, Dall.

Genus—Crassatewiitns, J. F. Kriiger, 1823.
(‘ Geschichte d. Urwelt.,’ ii, p. 466.)

CRASSATELLITES DIVISIENSIS, sp. nov. Plate XIX, fig. 1.

Description.—Shell subquadrate, very inequilateral, moderately long, convex,
but with flattened sides, carimate. Anterior margin regularly rounded; ventral
margin nearly straight, oblique to the postero-dorsal margin; posterior margin
convex, oblique, forming an obtuse angle with the postero-dorsal margin, which is
nearly straight. _Umbones rather prominent, curved anteriorly. Carina rounded,
forming a gentle curve between the umbo and the postero-ventral angle.
Posterior area moderately large, apparently not divided by a median rib. Lunule
deep.

Ornamentation consists of numerous, strong, regular, concentric ribs, separated
by shallow furrows. On the posterior area the ribs appear to be narrower.
Length 45 mm. ; height 37 mm.

Affinities—This species shows some resemblance to C. Guerangert, d’Orbigny,*

1 OC, Geinitzii, VOrbigny, ‘ Prodr. de Pal.,’ vol. ii (1850), p. 239. For references to Geinitz’s
figures see above (p. 124).

2 «Die Verstein. der bihm. Kreideformat.,’ pt. 2 (1846), p. 4, pl. xxxii, fig. 16. C. corrugata,
Reuss, ‘ Geogn. Skizzen aus Boéhmen,’ vol. ii (1844), p. 190; Giimbel, ‘ Abhandl. d. k. bayerisch. Akad.’
(Miinchen), vol. x (1868), p. 568. Cardita (Venericardia) bohemica, Griepenkerl, ‘Senon. Konigs-
lutter’ (‘ Palzont. Abhandl.,’ vol. iv, 1889), p. 58. See also C. Cottaldina, VOrbigny, ‘ Prodr. de
Pal.,’ vol. ii (1850), p. 161.

3 *Mollusk. Untersen. v. Braunschweig u. Isede’ (1898), p. 55, pl. vii, figs. 10—12.

4 «Pal. Franc. Terr. Crét.,’ vol. iii (1844), p. 76, pl. celxy, figs. 1,2; Guéranger, ‘ Album Paléont.
de la Sarthe’ (1867), p. 13, pl. xvi, fig. 11.

CRASSATELLITES. 129

but is more inequilateral, the ventral margin is nearly straight, the posterior
margin is more oblique, and the posterior area is relatively smaller. It is much
more inequilateral than C. regularis, @Orbigny.' C. divisiensis also resembles
some of the varieties of C. macrodonta (Sowerby)* from Gosau.

Distribution—Upper Greensand (zone of Schlenbachia rostrata) of Devizes.
An imperfect specimen from Warminster (zone of Pecten asper) probably belongs
to this species.

CRASSATELLITES VINDINNENSIS (d’Orbigny), 1844. Plate XIX, figs. 2, 3.

1844. CRASSATELLA VINDINNENSIS, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii,
p. 79, pl. eelxvi, figs. 1—3.

1850. _ VENDINNENSIS, d’Orbigny. Prodr. de Pal., vol. ii, p. 160.

1867. — vinpInnEnsIs, L. Guéranger. Album Paléont. de la Sarthe,
p. 18, pl. xvi, figs. 9, 10.

? 1868. C. W. Giimbel. Geogn. Beschreib. Konigreichs
Bayern, vol. ii, p. 766.
1871. - F. Stoliczka. Paleont. Indica, Cret. Fauna 8.

India, vol. iii, p. 294.

Description—Shell subquadrate, but trigonal without the posterior area, very
inequilateral, convex, with rounded carina. Anterior margin rounded, passing
gradually into the slightly curved ventral margin; posterior margin oblique, some-
what sinuous; postero-dorsal margin nearly straight, forming an obtuse angle with
the posterior margin. Lunule elongate, deep. Umbones prominent, incurved.
Posterior area of moderate size, divided by a median rib into two parts, of which
the anterior is concave.

Ornamentation consists of strong, regular, concentric ribs, separated by narrow
furrows. On the posterior area the ribs become very narrow and more or less
lamellar, and the interspaces are broad and flat.

Measurements :

(1) (2)
Length . : : 31 : : 30 mm.
Height . : 26 ; : 2 Gaeees

(( ike 2) Dunscombe.

Affinities This species is related to C. ligeriensis, d’Orbigny,’ and C. Gueran-

1 Op. cit., p. 80, pl. celxvi, figs. 4—7.
2 Zittel, “ Bivaly. d. Gosaugeb.” (‘Denkschr. d. k. Akad. Wien, Math.-Nat. Cl.,’ vol. xxv, pt. 2,
1866), p. 150, pl. viii, figs. 2, 3.
8 «Pal. Franc. Terr. Crét.,’ vol. iii (1844), p. 77, pl. eclxv, figs. 3—5 ; Guéranger, ‘ Album Pal¢ont.
de la Sarthe’ (1867), p. 13, pl. xvi, fig. 12.
17

130 CRETACEOUS LAMELLIBRANCHIA.

geri, VOrbigny,! but the posterior margin is more oblique and the posterior area
relatively smaller.

Remarks.—The lamellar ribs on the posterior area are not mentioned by
WVOrbieny, but attention is called to them by Guéranger.

I have seen only five specimens, which were collected by the late C. J. A. Me¥er,
and are now in the Sedgwick Museum, Cambridge.

C. vindinnensis is the type of Conrad’s? genus Pachytherus.

T'ypes.—From the Cenomanian of Rouen and Le Mans.

Distribution. —Cenomanian (Meyer's Beds 10 and 12) of Dunscombe, Devon.

Genus—AnrHonya, WW. M. Gabb, 1864.

(‘ Geol. Surv. California, Paleont.,’ vol. i, p. 181, pl. xxx, fig. 236.)
ANTHONYA CANTIANA, sp. nov. Plate XIX, figs. 4, 5.

Description.—Shell elongate, tapering posteriorly, very inequilateral, much
compressed. Anterior margin slightly convex. Ventral margin long, moderately
convex. Posterior margin short, truncate, forming angles with the ventral and
dorsal margins. Postero-dorsal margin concave. Umbones acute, near the anterior
end. A faint carina passes from the umbo to the postero-ventral angle and cuts
off a flattened or slightly concave postero-dorsal area.

Ornamentation consists of numerous narrow, regular, concentric ribs over the
whole surface of the shell. The ribs are separated by furrows of greater width
than themselves.

Measurements :

(1) (2)
Length . ; : Sb , : 27 mm.
Height . ‘ : 27 : : Heh ss

(1, 2) Folkestone Beds, near Copt Point.

Affinities —Vhis species is distinguished from A. Cornuelianw (VOrbigny)® by
the shorter anterior part of the shell, the smaller apical angle, and by the ribs,
which are of equal or nearly equal strength over the whole surface. It is less

elongate and has asmaller apical angle than the type species A. cullviformis, Gabb.

1 Op. cit., p. 76, pl. cclxv, figs. 1, 2; Guéranger, op. cit., p. 13, pl. xvi, fig. 11.

2 *Amer. Journ. Conch.,’ vol. v (1869), p. 47.

8 «Pal. France. Terr. Cr¢t.,’ vol. iii (1844), p. 74, pl. celxiv, figs. 7—9; referred to Ptychomya by
Pictet and Campiche, ‘ Terr. Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser. 4, 1866), p. 357; E. G. Skeat
and V. Madsen, “Jur. Neoc. and Gault Boulders in Denmark” (* Danmarks geol. Undersdg.,’ vol. 11,
No. 8, 1898), p. 178, pl. vi, fig. 13.

CYPRINA. 15]

Remarks.—Onuly two specimens have been seen, both of which were collected
by Mr. H. Keeping, and are now in the Sedgwick Museum, Cambridge.
Distribution.—Folkestoue Beds, near Copt Point, Folkestone.

AntHOoNYA, sp. Plate XIX, fig. 6.

Description.—Shell elongate, tapering posteriorly, very inequilateral, greatly
compressed. Anterior margin convex, rounded, passing gradually into the slightly
curved ventral margin. Posterior margin short, truncate, forming angles with the

ventral and dorsal margins. Postero-dorsal margin long, slightly concave. Umbones

5 *

sharp, anterior. Caria indistinct. Postero-dorsal area narrow. Surface of shell
smooth, except for growth-lines, which are rather more distinct near the anterior
margin than elsewhere.

Length, 38 mm. Height, 15 mm.

Affinities —This species appears to be closely allied to A. Cornueliana (dW Orbigny),!
but does not possess the concentric ribs near the anterior margin. It differs from
A. cantiana, sp. noy., in the greater length of the anterior part of the shell, the
greater curvature of the anterior margin, the larger apical angle, and the absence
of concentric ribs.

Remarks.—A left valve is the only specimen seen.

Distribution.—Lower Greensand (Crackers) of Atherfield.

Family—CY PRINID AS, Lamarck.

Genus—Cyrnrina, Lamarck, 1818.

(‘ Anim. sans Vert.,’ vol. v, p. 556)
Cyprina Saussurt (Brongniart), 1821. Plate XIX, figs. 7—13.

1821. Donacrres Saussurtr, A. Brongniart. Ann. des Mines, vol. vi, p. 555, pl.
vii, fig. 5 (non Venus Saussurii,

Goldfuss, 1840).
1854. Macrra saussurt, HL. Renevier. Mén. géol. sur la Perte-du-Rhoéne, p. 24.
1856. Cyprina Saussun, F. J. Pictet and E. Renevier. Foss. Terr. Aptien
(Matér. Pal. Suisse,
BOP), pitas. (pk

villi, figs. 1—2.

1 For references see p. 150, footnote 3.

132 CRETACEOUS LAMELLIBRANCHIA.

1865. Cyprrna Saussurt, F’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal.
Suisse, ser. 4), p.
220.

i H. Coquand. Mon. Aptien de Espagne, p. 113.

Description.—Shell usually of small or moderate size, sub-triangular, rounded,
often cyreniferm, convex, more or less considerably inequilateral. Lunular margin
of moderate length, concave. Anterior margin regularly rounded, passing gradu-
ally into the convex ventral margin. Posterior margin short, often more or less
rounded, sometimes truncate, forming an angle with the ventral margin, and not
sharply limited from the long postero-dorsal margin. Umbones prominent, broad.
Carina rounded, sometimes rather indistinct. Postero-dorsal area narrow.
Lunular region deep, indistinctly limited. _ Eseutcheon elongate, bounded by an
inconspicuous carina. Hinge not seen. Ornamentation consists of growth-lines
and numerous minute radial ribs.

Measurements :
GQ) @) (8) (4) (5) (eX) (8) (9)
Length . 52 49 40 3885 388 33 26 255 24mm.

Height . 40 40 31 33 OL. 287221) 25) 9
Thickness 384 31 27 26 20 16 TAG,

(1, 2) Perna-bed, Atherfield.
(8—9) Crackers, Atherfield.

Affinities —This species is related to C. cuneata (see p. 134), but the outline of
the shell is less distinctly triangular, the sides are less flattened, the ventral margin
is more convex, the umbones are broader and not so high, the lunular margin is
not so long, and the carina is less distinct.

Remarks.—Vhe relative height and length of the shell, and consequently the
outline, vary considerably.

Much larger and more globose specimens (Plate XIX, fig. 13) im which the
carina is indistinct, are associated with the normal forms of C. Saussuri, but are
less abundant. At first sight, especially when the shell is not quite perfect, these
appear to be distinct from C. Saussuri, but after comparing a number of speci-
mens I am led to the conclusion that they are only old individuals which have
attained a large size.

Examples of C. Saussurt from Atherfield were identified by Pictet and
Campiche, but, hitherto, no record of the species appears to have been made by
any English writer.

T'ype.—F¥rom the Aptian of the Perte-du-Rhéne.

Distribution—Lower Greensand (Perna-bed and Crackers) of Atherfield.

Atherfield Beds of Haslemere and Redhill.

Palxontographical Society, 1907.

Peel OUN OG RA Pa

OF THE

CRETACEOUS LAMELLIBRANCHIA

ENGLAND.

BY

HENRY WOODS, M.A.

UNIVERSITY LECTURER IN PALHOZOOLOGY, CAMBRIDGE,

VOL. If. PART Iv.

CYPRINIDA, ISOCARDIIDH, LUCINIDA, CORBIDA, UNICARDITDA,
TELLINIDA, MACTRIDH, AND VENERIDA.

Paces 1383—180; Pratrs XX—XXVII.

LONDON:
PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY

1907.

ee ms :
sons

PRINTED BY ADLARD AND SON, LONDON AND DORKING.

wr aie ie 1

i Ag ees.

yy

CYPRINA. is

co
Co

Cyprina Sepewickt (Walker), 1866. Plate XIX, fig. 14. Plate XX, figs. 1-5.

1866. SpH#ra Sepewrcxi, J. F. Walker. Ann. Mag. Nat. Hist., ser. 3, vol.
Xvili, p. 386, pl. xiii, figs. 1, 2.
1867. Cyprina ancutata, var., H. G. Seeley. Thid., ser. 3, vol. xx, p. 27.
1875. — Sepewicnir, W. Keeping in T. G. Bonney. ‘ Cambridgeshire
Geology,’ p. 68.
1883. — —- W. Keeping. Foss., ete., Neoc. Upware and Brick-
hill, p. 123, pl. vi, fig. 12.

Description.— Shell more or less oval, sometimes sub-triangular, rounded, inflated,
slightly or moderately inequilateral; length as a rule not greatly exceeding the
height. Lunular margin of moderate length, concave. Anterior margin rounded,
passing gradually into the convex ventral margin. Postero-dorsal margin moderately
convex. Umbones prominent, broad, curyed inward and forward. Carina absent
or indistinct. Postero-dorsal region convex, rounded. Lunule large, ovate,
bounded by a faint groove. Escutcheon long, bounded by a more or less distinct
carina. Ornamentation consists of growth-lines.

Measurements :

(1) (2) (8) (4) (5) (6) (7) (8) (9)
Length . 39 38 37 37 384 32 31 27 23 mm.
Height . 34 31 31 32 31 265 27 24 20 ,,

Thickness 29 -25 26°5 Qo z
(1—9) Lower Greensand, Upware.

Affinities.—This species is closely related to, and may perhaps be only a local
variety of C. Saussuri (see above). The chief points in which it differs from the
latter are (1) the carina is absent or indistinct, (2) the posterior margin is
relatively higher, (3) the valves are usually more inflated, (4) the shell is usually
less triangular in outline and less inequilateral.

Remarks.—The examples of C. Sedgwicki vary in relative height and length,
and consequently in outline. The longer forms approach (. Saussu7i more nearly
than the shorter forms.

This species was placed in the genus Sphara by Mr. J. F. Walker, but was
subsequently referred to Cyprina by Seeley and by W. Keeping.

Type.—From Potton, in Mr. J. F. Walker’s collection.

Distribution.—Lower Greensand of Upware and Potton.

Cyprina ontusa, Keeping, 1883. Plate XX, fig. 6.

1883. Cyprina ontusa, W. Keeping. Foss., ete., Neoc. Upware and Brickhill, p
124, pl. vi, fig. 13
1S

154. CRETACEOUS LAMELLIBRANCHIA.

Remarks.—C. obtusa, of which I have seen two specimens only, closely re-
sembles some forms of (. Saussuri, but differs in having narrower and less curved
umbones. It also resembles the more elongate forms of C. Sedgwick.

Type.—In the Sedgwick Museum.

Distribution.—Lower Greensand of Upware.

Cyprina cunrATA, Sowerby, 1836. Plate XX, figs. 7-12.

1836. Cyprina cunnata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp.
240, 341, pl. xvi, fig. 19.

1849. — TRIANGULARIS, 7’. Brown. Foss. Conch., p. 207, pl. Ixxxy, fig. 2.
1850. _ cunnata, A. d’Orbiqny. Prodr. de Pal., vol. ii, p. 161.
1854. — —s J. Morris. Cat. Brit. Foss., ed. 2, p. 199.

1865. - — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal.
Suisse, ser. 4) p.

230.
1870. -- — F.. Stoliczka. Paleont. Indica, Cret. Fauna §. India,
vol. iii, p. 193 [| Anisocardia (Veniella) }.

Description.—Shell of small or moderate size, triangular, convex with flattened
sides, carinate, considerably inequilateral. Lunular margin long, concave. Anterior
margin regularly rounded. Ventral margin only slightly curved, sometimes
with the posterior part concave. Posterior margin short, truncated, almost
straight, nearly parallel to the height of the shell, forming a right angle with
the ventral margin and an obtuse angle with the long postero-dorsal margin.
Umbones prominent, high, curved considerably inward and forward. A distinct, but
rounded, carina extends in a gentle curve from the umbo to the postero-ventral
angle. In front of the carina the shell is sometimes slightly concave. Postero-
dorsal area narrow, sloping steeply except near the posterior margin. Lunular
region deep, indistinctly limited. Escutcheon elongate, bounded by a small carina.
Ornamentation consists of very fine growth-lines at regular intervals.

Measurements :

@ @) @&) @® ©) © @ (8) = (@) G9)
Length . 48 36 35 31 29 265 26 26 23 20mm.
Height . 40 29 29 26 24 20% 21 195 20 16
(1—10) Blackdown.

bo bo

39

Affinities —The differences between C. Saussuri and this species are given
above (p. 132).
The form from the Meule de Bracquegnies which was referred to C. angulata,

: =

CYPRINA. 15

Gr

Sowerby, by Briart and Cornet,' appears to be more nearly related to C. cuneata
than to C. angulata.

C. securiformis, Sharpe,” is similar to C. cuneata, but its ventral margin has a
much greater curvature.

C. cuneata is mentioned by Stoliczka as a typical example of the sub-genus
Veniella, Stoliczka.* The anterior right cardinal tooth, however, does not appear
to be so strongly developed as in the type of Veniella.

T'ypes.—The types came from Blackdown, but cannot now be found.

Distribution.—Upper Greensand (zone of Schlwnbachia rostrata) of Blackdown
and Haldon. Upper Greensand (Me¥er’s Bed 2) of Weston Mouth (Devon).

CYPRINA CLAXBIENSIS, sp. nov. Plate XXI, fig. 2; Plate XXIV, fig. 1.

Description.—Shell large, stout, oval, rather elongate, considerably inequilateral,
moderately convex. Antero-dorsal margin short, straight or slightly concave.
Anterior margin well rounded, passing gradually into the convex ventral margin.
Posterior margin oblique, sub-truncate, more or less rounded. Postero-dorsal
margin rather long, slightly convex. Umbones broad, curved anteriorly, with a
rounded carina extending to the postero-ventral extremity, and limiting a flattened
or somewhat convex postero-dorsal area which slopes rapidly to the postero-
dorsal margin, but more gradually to the posterior margin. Lunular region
excavated, not limited. Ornamentation consists of small concentric ribs.

Hinge: in the right valve the anterior cardinal is conical, larger than the
median cardinal, and placed below and separated from the latter; the posterior
cardinal is oblique, laminar, and divided by a furrow. In the left valve the
anterior and median cardinals are stout, the posterior cardinal is oblique and
laminar.

Measurements (approximate) :

(1) (2) (3)
Length : 99 : 80 : 74 mm.
Height 75 : 64. bow ss

Affinities —This species resembles C. Constanti, Dollfus,* from the Kimeridgian,
1 Meule de Bracquegnies (‘Mém. cour. et Mém. des. Sav. ¢trangers,’ vol. xxxiv, 1867), p. 68, pl.
viii, figs. 26—28.
2 «Quart. Journ. Geol. Soc.,’ vol. vi (1850), p. 182, pl. xxii, figs. 1—3. C. globosa, Sharpe (Ibid.,
p. 182, pl. xv, fig. 1) is recorded by Morris from Blackdown, but I have seen no example of if.
3 ‘Paleont. Indica, Cret. Fauna S. India,’ vol. iii (1870), p. 189. See also Meek, * Invert. Cret.
and Tert. Foss. U. Missouri’ (1876), pp. 147—152.
4‘Faune Kimmérid. du Cap de la Héve’ (1863), p. 65, pl. x, figs. 6—8. De Loriol and Pellat,
‘Mon. Etages supér. Jurass. de Boulogne-sur-Mer ’ (1874), p. 42, pl. xii, fig. 14.

156 CRETACEOUS LAMELLIBRANCHIA.

but is much larger and stouter, and the lunular region is more deeply excavated ;
also the umbones appear to have a greater anterior curvature.

Type.—From Benniworth Haven, in the Sedgwick Museum.
Distribution—Claxby Ironstone (zone of Belemnites lateralis) of Benniworth

Haven and Donnington.

CYPRINA TEALBIENSIS, sp. nov. Plate XX, fig. 13a, b.

Description—Shell very thick, large, elongate, oval, regularly convex, very
inequilateral. Antero-dorsal margin concave. Anterior margin rounded, curving
rapidly, passing gradually into the ventral margin. Posterior margin rounded,
forming an obtuse angle with the long, slightly convex postero-dorsal margin.
Umbones broad, anterior, curved inward. <A faint carina extends from the umbo
to the posterior end. Lunular region deep. Escutcheon large, deep, limited by a
strong carina. Ornamentation consists of growth-ridges.

Measuremeits :

(1) (2)
Length . : ; : 105 F ; 62 mm.
Height . . : ‘ 82 . : AQ .,

(1, 2) Tealby Limestone.

Afiinities—In its elongate form, and deep, carinate escutcheon this species
resembles C. boloniensis, de Loriol,! from the Portlandian.

Remarks.—There are two specimens in the Sedgwick Museum and one in the
British Museum. ‘The hinge has not been seen.

Distribution —Tealby Limestone of Walesby and Claxby, Lincolnshire.

Cyprina, sp. Plate XXI, fig. 3.

A large Cyprina from the Tealby Limestone of Claxby is known by a right
and a left valye, now in the Sedgwick Museum, and appears to belong to a distinct
species. It shows some resemblance to C. augulata, Sowerby (see page 141), but
differs from that species in the greater ventral slope of the postero-dorsal margin ;
the greater obliquity of the posterior margin; tke smaller curvature of the
umbones ; the longer and less concave antero-dorsal margin ; and in the absence
of a carina cutting off a postero-dorsal area. The surface of the shell is
imperfectly preserved, but in places there is evidence of well-marked growth-
ridges. Length, 92mm. Height, 80 mm.

1 De Loriol and Pellat, ‘ Portlandien de Boulogne-sur-Mer ’ (1866), p. 54, pl. v, fig. 9.

CYSERTINAG 137
Cyprina, sp. Plate XX, fig. 14.

A few specimens of a small Cyprina, with the shell imperfectly preserved,
have been found in the Speeton Clay (D, 1).

CypriNA ANGLICA, sp. nov. Plate XX, figs. 15,16. Plate XXI, fig. la, b.

Description.—Shell of moderate size, oval, inflated, very inequilateral. Anterior
margin rounded, forming a continuous curve with the convex ventral margin.
Posterior margin less convex than the anterior, sometimes slightly truncated, more
or less oblique, usually curving gradually to join the ventral margin. Postero-
dorsal margin long, slightly convex. Antero-dorsal margin short, nearly straight.
Umbones broad, anterior, curving inward and forward. — Postero-dorsal part of
shell slightly compressed ; carina absent or indistinct. Lunule ovate, depressed,
more or less distinctly limited. Ornamentation consists of growth-lines.

Measurements :

(1) (2) (3) (4) (5) (6)
Length 42, : Ad ‘ 38 , 32 ; 27 ; 21 mm.
Height 35 33 ; 31 24, : 20 : 145;
Thickness 28 : 26°b) 24 165 9: 1: Ney ht tees

(1—6) Crackers, Atherfield.

Affinities —C. anglica does not appear to be closely related to any other
English species. Externally it shows some resemblance to C. anguluta, Sowerby
(see below), but is of much smaller size, more elongate, with a more or less
distinctly limited lunule, and either without a carina or with an indistinct carima
near the umbones.

Remarks.—Nearly all the specimens show the two valves united, so that the
hinge and pallial line do not appear to have been seen by previous workers ; this
probably accounts for the fact that in several collections the species has been
referred to the genus Venus. A left valve, from which I have removed the matrix,
shows that the hinge agrees with Cyprina, and that there is no pallial sinus.

T'ype.—In the Sedgwick Museum, Cambridge.

Distribution.—Lower Greensand (Crackers) of Atherfield. Atherfield Beds of
Peasemarsh.

Cyprina (VENILICARDIA) PKOTENSA, sp. nov. Plate XXI, figs. 4—7. Text-figs.
20; Pil.

1845. Cyprina ancuuata, FE. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 240

(partim).

158 CRETACEOUS LAMELLIBRANCHIA.

Description.—Shell large, oval, convex, moderately mequilateral, anterior part
produced. Antero-dorsal margin concave. Anterior margin rounded, passing
gradually into the convex ventral margin which curves upward to joi the
posterior margin. Posterior margin rounded, sometimes forming a large and
rounded angle with the ventral margin, but sometimes passing into it gradually.
Postero-dorsal margin convex. Postero-dorsal part of valves compressed, some-
times limited by an indistinct carina. Umbones prominent, curving forward and
inward. Lunule indistinctly limited. Escutcheon narrow, deep, with a sharp
edge. Ornamentation consists of growth-lines.

Fic. 20.—Cyprina (Venilicardia) protensa, sp. nov. Lower Greensand (Perna-bed), Atherfield.
Sedgwick Museum. Right valve. x +4.

Measurements :

(1) (2) (3) (4) (5) (6)
Length 106 ; 105 : 103 F 99 ; ae 49 mm.
Height 84 , 89 5 91 : 88 : 60 E AQ ,,

(1—5) Perna-bed, Atherfield.
(6) Crackers, Atherfield.

Affinities —The characters which distinguish this species from C. angulata,
Sowerby, are: the umbones are less anterior and the shell is less inequilateral ;
the umbonal part of the shell is relatively smaller; the carina is less distinct; the
anterior part of the shell is more produced; the posterior part is more rounded ;
the ventral margin has a greater curvature; the shell is less inflated, so that the
marginal parts of the valves meet at a smaller angle. ‘The anterior part of the
shell resembles that of C. truncata, but the posterior part is more rounded, and

CYPRINA. 139

the postero-dorsal margin has a greater ventral slope. C. protensa belongs to the

sub-genus Venilicardia, Stoliezka.!
T'ype.—In the Sedgwick Museum; from the Peria-bed of Atherfield.
Greensand : Perna - bed

Distribution.—Lower of Atherfield and Sandown.

Lower Greensand (Perna-bed), Atherfield.

Fira. 21.—Cyprina (Venilicardia) protensa, sp. nov.
Sedgewick Museum. Right valve. x

Crackers of Atherfield. Ferruginous Sands of Shanklin (Meyer Collection).

Atherfield Beds of Peasemarsh.

Cyprina Sowersyt, d’Orbigny, 1850. Plate XXI, figs. 8,9. Text-fig. 22.

Trans. Geol. Soc., ser. 2, vol. iv,

p- 128.
Quart. Journ. Geol. Soe., vol. i, p. 240

1836. Cyprina anaunata, J. de C. Sowerby.

E. Forbes.

1845. --
(partin).
1850. Sowersyt, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 78.
1854. — ANGuLATA, J. Morris. Cat. Brit. Foss., ed. 2, p. 199 (partim)
Measurements :
(1) (2) (3) (4)
Length : ‘al A OA. 59 ‘ 55 mm.

60 E 5] 52 a 55

Height
(1, 2, 4) Hythe Beds, Hythe.

(3) Lower Greensand, near Atherfield

1 * Paleont. Indica, Cret. Fauna S. India,’ vol. iii (1870), p. 190

140 CRETACEOUS LAMELLIBRANCHIA.

Remarks.—Internal casts of Cyprina are found commonly in the Hythe Beds
of Hythe, ete. Those from the “rag” have their original form well preserved, but
the specimens found in the softer greensand beds are more or less crushed. One
example of the same species with the shell preserved has been obtained from the
Lower Greensand between Atherfield and Blackgang. The form of the shell

Fia. 22.—Cyprina Sowerbyi, VOrb. Lower Greensand, Parham Park. British Museum, No. 5933.
Internal cast. Left valve, and dorsal view of both valves. x 4.

resembles that of (. lineolata (see below), but the anterior curvature of the
umbones is considerably less, and the postero-dorsal margin of the shell is less
convex. It is difficult to determine satisfactorily the affinities of this species until
more specimens with the shell have been obtained. It may be identical with the
form from the Upper Aptian of Ste. Croix and the Perte-du-Rhéne referred by

CYPRINA. 141

Pictet and Roux! to C. ervyensis, Leymerie, and by Pictet and Campiche* to (.
angulata, Sowerby. Hnglish examples were identified with C. angulata by J. de C.
Sowerby, Forbes, and Morris, but were regarded by d’Orbigny as belonging to a
distinct species which he named (. Sowerbyi, and mentioned as types the
specimens collected by Fitton from the Hythe Beds near Folkestone. C. Sowerbyi
also resembles C. neocomiensis, d’Orbigny.*

Distribution.—Hythe Beds of Hythe. Sandgate Beds of Parham Park. Lower
Greensand between Atherfield and Blackgang.

eee) oman (Sowerby), 1814. Plate XXII, figs. 1—4.
Text-figs. 23, 24.

1814. Venus aneuara, J. Sowerby. Min. Conch., vol. i, p. 145, pl. Ixv.
1828. Cyprina ANGULATA, J. Fleming. Hist. Brit. Animals, p. 444.

1836. — — J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
p- 240.

1850. — -- A. d’Orbigny. Prodr. de Pal., vol. ii, p. 161.

1854. = — J. Morris. Cat. Brit. Foss., ed. 2, p. 199 (partim).

1870. — —- F, Stoliczka. Paleont. Indica, Cret. Fauna S. India,

vol. ii, p. 193.
Non 1868. — = A. Briart and F. L. Cornet. Meule de Braequegnies

(Mem. cour. et Mém. des Say. ¢étrangers,

vol. xxxiv), p. 68, pl. viii, figs. 26—28.

Description.—Shell large, sub-quadrate, rounded, very inequilateral, moderately
inflated. Anterior margin rounded, passing quickly into the ventral margin,
with which it forms a regular and continuous curve. Posterior margin more or
less truncated, slightly or moderately convex, usually oblique, and forming an
obtuse angle with the postero-dorsal margin. Umbones large, broad, anterior.
A more or less distinct carina passes from the umbo to the postero-ventral
angle, cutting off a postero-dorsal area, which slopes rather rapidly to the posterior
margin. Lunular region more or less depressed, not limited. Escutcheon narrow,
deep, limited by a sharp carina.

Ornamentation consists of growth-lines.

In the right valve the posterior cardinal tooth is large and divided; the
median cardinal is smaller than the anterior cardinal, and in most forms adjoins

1 Pictet and Roux, ‘ Moll. Foss. Gris verts de Gentve’ (1852), p. 444, pl. xxxiv, fig. 1.

‘Terr. Crét. de Ste. Croix’ (1865), p. 221.

8 «Pal. Franc. Terr. Crét.,’ vol. iii (1847), pp. 98, 759, pl. cclxxi.

bernensis, Leymerie, see d’Orbigny, ‘ Prodr. de Pal.,’ vol. ii (1850), p. 77.

w

Afterwards referred to C.

19

14.2 CRETACEOUS LAMELLIBRANCHIA.

the postero-dorsal side of the latter, but in examples in which the umbones are
more anterior in position the median cardinal is dorsal to the anterior cardinal,
and is almost continuous dorsally with the posterior cardinal tooth.

Measurements :

(1) (2) (3) (4) (5) (6) (7) (8)
Length. 103° . 104 . 99> -7 “98 92) 496. a. S90 2 ee ce ae

Height. 92°. 90. 86 = B61 660, A79G oe
(1—8) Blackdown.

Ajjinities—Specimens of Cyprina from the Aptian and Gault of the Perte du
Rhone and Ste. Croix were referred by Pictet, Roux, and Renevier, to C. ervyensis,
Leymerie, but were subsequently identified with C. angulata by Pictet, Renevier,

Fic. 23.—Cyprina (Venilicardia) angulata (Sow.). Upper Greensand, Blackdown. Museum of Practical
Geology, No. 18698.. Right valve, and anterior view of both valves. x +4.

and Campiche.' Pictet and Campiche, after an examination of specimens from the
Gault of Nisvre and Yonne, came to the conclusion that C. ervyensis, as described
and figured by Leymerie? and d’Orbigny,® must be regarded as a synonym of
CU. angulata. I have had no opportunity of comparing French specimens with
examples from Blackdown, but so far as I can judge from the figures of C. ervyensis
there appear to be some differences, consequently I do not at present feel justified
in including C. ervyensis as a synonym of C. angulata.

1 Pictet and Roux, ‘Moll. Foss. Grés verts de Gentve’ (1852), p. 444, pl. xxxiv, fig. 1. Pictet and
Renevier, ‘ Foss. Terr. Aptien’ (‘Matdé. Pal. Suisse,’ ser. 1, 1856-58), pp. 75,177. Pictet and Campiche,
‘Terr. Crét. Ste. Croix’ (‘Matér. Pal. Suisse,’ ser. 4, 1865), p. 221.

2 *Mém. Soe. géol. de France,’ vol. v (1842), pp. 5, 25, pl. iv, figs. 6, 7.

3 «Pal. Frang. Terr. Crét.,’ vol. iii (1844), p. 102, pl. celxxiv.

CYPRINA. 143

C. angulata of Briart and Cornet appears to be closely related to C. cwneata,
Sowerby (see p. 134).

C. (Venilicardia) Jukesi, de Loriol,! from the Gault of Cosne, resembles some
forms of C. angulata.®

Remarks.—C. angulata varies in its relative height and length, and in the
position of the umbones. The shell is usually stout, but occasionally rather thin.
Sowerby gives a good figure of C. angulata, except that the teeth, as pointed out
by Stoliezka, are not correctly drawn.’

Fig. 24—Cyprina (Venilicardia) angulata (Sow.). Upper Greensand, Blackdown. Sedgwick Museum.
Right valve x +. The hinge of this specimen is shown on Plate XXII, fig. 2.

Types.—F rom the Upper Greensand of Blackdown, in the British Museum.
Distribution.—Upper Greensand (zone of Schlenbachia rostrata) of Blackdown
and Haldon. Recorded by Jukes-Browne from the Lower Gault of Wiltshire, and
from the Upper Greensand of the Isle of Wight.

Cyprina (VENIEICARDIA) LINEOLATA (Sowerby), 1813. Plate XXII, figs. 5—8.
Plate XXIII, figs. 1, 2.

1811. Venvs castrensis, J. Parkinson. Organic Remains, vol. iii, p. 187 (non

V. castrensis, L.).

1 «Gault de Cosne’ (1882), p. 68, pl. ix, fig. 1.
2 Morris records Cyprina globosa, Sharpe, from the Greensand of Blackdown, but T have not seen
any specimen from that locality. Morris, ‘Cat. Brit. Foss.,’ ed. 2 (1854), p. 199. Sharpe, ‘ Quart.
Journ. Geol. Soc.,’ vol. vi (1850), p. 182, pl. xv, fig. 1.

3 From the remark on Sowerby’s figure made by Briart and Cornet (p. 69) T can only conclude
that they had not seen specimens of C. angulata.

144 CRETACEOUS LAMELLIBRANCHIA.

1813. Venus tineouata, J. Sowerby. Min. Conch., vol. i, p. 57, pl. xx (upper
figure).
1828. — — J. Fleming. Hist. Brit. Animals, p. 449.
1836. Cyprina rostrata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp.
240, 341, pl. xvii, fig. 1.

1836. Cyrnerra LinnoLata, Sowerby. Ibid., p. 240.

1850. Cyprina rostrata, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 161.

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 199.

1854. Cyrnerna tingonata, Morris. Ibid., p. 200.

1865. Cyprrna rostrata, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser.
4), pp. 222, 229.

1870. — — F. Stoliczka. Palseont. Indica, Cret. Fauna 8. India,
vol. 11, p. 198 (Venilicardia).
1907. — tinzouata, PR. B. Newton. Proc. Malacol. Soc., vol. vii, p. 284,

pl. xxiv, fig. 14.
Non 1844. — — A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 98,
pl. eclxxi (Cyprina neocomiensis,

VOrbigny, Ibid., p. 759).

Measurements :

(1) (2) (3) (4)
Length : 71 67 66 52 mm.
Height 5 61 : 60 58 43 ,,

(1—4) Blackdown.

Affinities—This species differs from C. angulata im its more prominent and
more strongly curved umbones, in the shorter posterior margin and the greater
slope of the postero-dorsal margin, and in the more deeply depressed lunular
region. The hinge also differs: in the right valve the median cardinal tooth is
distinetly separated from the anterior cardinal and is dorsal to the latter and
continuous with the posterior cardinal tooth ; the latter is either undivided or the
division is indistinctly shown.

Remarks.—C. lineolata varies considerably in the prominence and curvature of
the umbones, and, as a result, in the outline of the shell. An extreme form was
figured by J. de C. Sowerby as the type of C. rostrata; im specimens in which the
umbones are less prominent and their anterior curvature less pronounced the out-
line of the shell becomes less triangular, and in some cases approaches that of C.
angulata, but the differences in the hinge of the right valve and the greater depth
of the lunular region appear to be present in all specimens.. The average size of
this species is considerably less than that of C. angulata.

The type of Venus lineolata, Sowerby (V’. castrensis, Parkinson), from Black-
down, agrees with the normal forms of C. rostrata, except for the presence of

CYPRINA. 145

numerous W-shaped markings on the surface. These appear to be due to the
structure of the shell (possibly connected with colour markings), since they are
seen only in specimens which are somewhat decorticated, and are in some cases
present on one valve but not on the other, or are seen on the dorsal but not on
the ventral part of a valve.

Stoliczka’ thought that Venus lineolata was probably identical with Cytherea
plana, Sowerby, but the hinge and pallial line of the former prove conclusively
that it belongs to the genus Cyprina.

Types.—From Blackdown; Venus lineolata in the British Museum ; (. rostrata
in the Bristol Museum.

Distribution Upper Greensand (zone of Schlenbachia rostrata) of Blackdown.

Cyprina (Veninicarpia) truncata (Sowerby), 1836. Plate XXIII, fig. 3.

1836. Venus? truncata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp. 242, 341, pl. xvii, fig. 3.
1850. — supTRUNCATA, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 159.
1854. Cyrmrerra truncata, J. Morris. Cat. Brit. Foss., ed. 2, p. 201.
1865. Venus susrruncara, I’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4), p. 190.
1870 — — F. Stoliczka. Paleont. Indica, Cret. Fauna S. India,
vol. i, p. 161 (Caryatis).

Affinities ~—C. truncata is closely allied to, and probably only a variety of
C. angulata. The shell is thinner, the posterior margin higher, and the anterior
part more produced than in C. angulata.

This species, or variety, has hitherto been referred to Venus or Cytherea, but
a specimen showing the hinge and pallial line proves that it is a Cyprina. The
hinge agrees with that of C. angulata.

An example collected by the late Rev. W. Downes (Plate XXIII, fig. 4) is
more elongated and more inflated than the type of C. truncata, but agrees in other
respects, and is probably only an individual variation.

Type.—From Blackdown ; in the Bristol Museum.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown.

Cyprina LIGERIENSIS, d’Orbigny, 1844.

Internal casts of a large Cyprina have been found in the Cenomanian
Sandstone of Wilmington,” Devon, and in the cherty blocks in the Eocene Gravel

1 «Cret. Fauna S. India,’ vol. iii (1870), pp. 160, 169.

2 Jukes-Browne, ‘Cret. Rocks of Britain,’ vol. ii (1903), p. 129

146 CRETACEOUS LAMELLIBRANCHIA.

(derived from the Upper Greensand) of Aller Vale near Torquay. They have
been identified with C. ligeriensis, @Orbigny,’ by Mr. Jukes-Browne, who has
compared them with examples of that species from the Cenomanian of Vimoutiers
and Orbiquet, and states that the agreement is very close. The English specimens
also resemble C. Noueliana, @Orbigny,’ of which a cast only is figured by
dOrbigny, and was at first regarded as C. ligeriensis. An example from
Wilmington is in the Sedgewick Museum. Others from Aller Vale are in the
Torquay Museum and in the Sedgwick Museum.

Cyprina (Ventnicarpta ?) quaprata, d’ Orbigny, 1844. Plate XXIII, figs. 6—9.

1840. Tsocarpra creracea, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 2, p. 53, pl. x1,
figs. 6, 7 (non Goldfuss).

1844. Cyprina quaprata, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. i, p. 104,

pl. celxxvi.

1850. — — — Prodr. de Pal., vol. ii, p. 161.

— _- — ° H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in
Deutschland, p. 156.
1865. -- a= F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p- 225, pl. exv, figs. 3—5.

1870. = — F. Stoliczka. WPalseeont. Indica, Cret. Fauna S. India,
vol. iii, p. 193.
1873. _ — H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palaonto-

eraphica, vol. xx, pt. 2), p. 62, pl. xvii,

fies. 14—16.
? 1877. - — A. Fritsch. Stud. im Gebiete der bohm. Kreideformat.
II Weissenberg. u. Malnitz. Schicht.,

p- 116, fig. 76.

? 1883. — — — Thid., ITI Iserschicht., p. 100, fig. 65.
1895. — — ET. Tiessen. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xlvii, p. 486.
1897. Ancrica — H. Woods. Quart. Journ. Geol. Soc., vol. lili, p. 390,

pl. xxvii, fig. 25, pl. xxviii, fig. 1.

Descviption—Shell sub-rhomboidal, much inflated, rather strongly carinate,
very inequilateral; length somewhat greater than height. Anterior margin
rounded, passing gradually into the slightly curved ventral margin. Posterior

1 «Pal. France. Terr. Crét.,’ vol. iii (1844), p. 103, pl. celxxv, figs. 1, 2; ‘ Prodr. de Pal.,’ vol. ii

(1850), p. 161; Guéranger, ‘Album Paléont. de la Sarthe,’ 1867, p. 15, pl. xvii, figs. 1, 5.
2 Op. cit. (1844), pl. celxxv, figs. 3, 4; op. cit. (1850), p. 195.

CYPRINA. 147

margin truncated, high. Postero-dorsal region flattened. Umbones prominent,
anterior, curved inwards. Lunular region excavated. Ornamentation consists of
concentric striz.
Measurements :
Q) (2) (3) (4) (5) (6) (7) (8) (9) (0) (1)
Tength. 54 46 37 35 26 238 46 40. 20 45 58 mm.
Height . 46 41 34 31 24 19 39 383 15 38 £52
; (1—6) Gault, Folkestone.
(7—9) Rye Hill Sand, Warminster.
(10) Chloritic Marl, Maiden Bradley.
(11) Base of Chalk, Chard.

39

Affinities —In C. ligeriensis, VOrbigny,! the umbones are less anterior in posi-
tion, and the angle between the posterior and the dorsal margins is larger than in
C. quadrata.

C. regularis, VOrbigny,* is distinguished from C. quadratu by its less inequi-
lateral and more regularly globose shell, by its less incurved umbones, and the
smaller truncation of the posterior end.

C. crassicornis (Agassiz)* possesses a relatively higher and less equilateral
shell, with more prominent umbones, which are not so much curved anteriorly
as in CU. quadrata.

Remarks.—The specimens from the Gault have the shell more or less perfectly
preserved, but most of the examples from higher beds are, like the type, in the
form of internal casts. The specimens found in the Chalk Rock are rather
imperfect, but do not appear to differ specifically from those found at lower
horizons.

Type.—The locality of the type is not given by d’Orbigny, but he records
specimens from the Cenomanian of Villers (Calvados), Rouen, St. Calais (Sarthe),
ete.

Distribution —Upper Gault of Folkestone. Upper Greensand (zone of Sehlan-
bachia rostrata) of Devizes (fide Jukes-Browne). Rye Hill Sand of Warminster.
Base of the Chalk of Chard. Chloritic Marl of Maiden Bradley and the Isle of
Wight. Chalk Rock of Morgan’s Hill near Devizes, Cuckhamsley, and Luton.

1 «Pal. Frane. Terr. Crét.,’ vol. iii (1844), p. 103, pl. eclxxv, figs. 1, 2 (not 3, 4).

2 Thid., p. 100, pl. celxxii, figs. 3—6 ; Pictet and Campiche, ‘ Foss. Terr. Crét. Ste. Croix’ (1865),
p- 224, pl. exv, figs. 1, 2.

8 ‘Etudes crit. Moll. Foss., Myes’ (1842), p. 36, pl. viii /, figs. 5—10; Pictet and Campiche, ‘Terr.
Crét. Ste. Croix’ (‘Matér. Pal. Suisse,’ ser. 4, 1865), p. 226, pl. exv, figs. 6—8.

148 CRETACEOUS LAMELLIBRANCHIA.

Genus—Trapezium, Megerle v. Mihlfeldt, 1811.
(‘ Naturf. Freunde zu Berlin Mag.,’ vol. v, p. 68.)

TRapEZium 2 AncADIFORME (Keeping), 1883. Plate XXIII, figs. 10, 11.

1883. CypricarpIA arcApirormis, W. Keeping. Foss. ete., Neoc. Upware and
Brickhill, p. 120, pl. vi, fig. 6.

Description.—Shell trapezoidal, inflated; length much greater than height.
Dorsal and ventral margins nearly straight and nearly parallel. Posterior margin
oblique, straight or slightly curved, forming an obtuse angle with the dorsal
margin and an acute but rounded angle with the ventral margin. Anterior margin
rounded. Umbones near the anterior end, much curved, with a strong, rounded
keel extending to the postero-ventral angle. The part in front of the keel is
slightly concave, giving a faint sinuosity to the ventral margin of the valve. The
triangular part dorsal to the keel is compressed and flattened, and slopes steeply to
the margin. Lunule cordate. Hinge not seen.

Ornamentation consists of small, rounded radial ribs, and, at intervals, strong
concentric laminar ridges ; both ribs and ridges are indistinct on the part dorsal to
the keel. Length 21 mm.; height 12°5 mm. ; thickness, 13 mm.

Ajfinities—This species is more elongate, and the carina is more angular than
in 7’. squamosum (see below).

Remarks.—The only examples seen are the type and a specimen in Mr. J. F.
Walker’s collection.

Type.—The type is in the Sedgwick Museum.

Distribution.—Lower Greensand, Upware.

TRAPHZLUM P squamosuM (Keeping), 1883. Plate XXIII, figs. 12—15.

1883. CypricarpiA squamosa, W. Keeping. Foss., ete., Neoc. Upware and Brick-
hill, p. 120, pl. vi, fig. 5.

Description—Shell rounded-oblong, much inflated, highest near the posterior
end. Dorsal margin nearly straight; the posterior forms a regular curve, which
passes into the slightly concave ventral margin. Dorsal part of anterior margin
concave, ventral part rounded. Umbones prominent, anterior, much curved. A
broad, rounded ridge extends from the umbo to the postero-ventral extremity and
divides the shell into two parts. The part in front of the ridge is shghtly concave,
the part above is larger and convex. Lunule cordate.

Ornamentation consists of small radial ribs, and, at rather distant imtervals,

TRAPEZIUM. 149)

strong concentric lamelle. The ornamentation is indistinct on the part above the
rounded ridge. Margin of valve crenulate.
Measurements :

(1) (2) (3) (4)
Length ; Gyo % 14. p hei). 12°5 mm.
Height : 12 : LI : 11 : LO ak
Thickness . 10 : 10 ; ING): pee ee 9

(1—4) Lower Greensand, Upware.

Affinities—Keeping compared this species with Cardita neocomiensis, VOrbigny,
to which it shows some resemblance in general form. But the faint radial ribs
and strong concentric lamella, as well as the character of the hinge, so far as it
can be made out, seem to connect this species with Trapezium rather than with
Cardita.

Type.—tIn the Sedgwick Museum.

Distribution.—Lower Greensand, Upware.

TRAPEZIUM ? sp. Plate XXIII, fig. 16.

1883. Cypricarpia striara, W. Keeping. Foss., etc., Neoc. Upware and Brickhill,
p. 119.

An imperfect left valve from the Lower Greensand of Upware, in the Sedgwick
Museum, was identified by W. Keeping with Cypricardia striata (Geimitz) * from
the Cenomanian of Saxony. ‘The ribs are féwer in number than in the examples
of CO. striata figured by Geinitz.

TRAPEZIUM TRAPEZOIDALE (Rémer), 1841. Plate XXIII, figs. 17—19.

1841. CrassarELLA TRAPEzoIDALIs, I’, A. Rimer. Die Verstein. d. nord-deutsch.
Kreidegeb., p. 74, pl. ix,
fie. 22.
? 1847. = — A. @Archiac. Mém. Soe. géol. de France,
ser. 2, vol. il, p- 302.

1850. Cyprina H. B. Geinitz. Das Quadersandst. oder
Kreidegeb. in Deutsch-
land, p. 158 (parti).

1854. CyprIcARDIA — A. @ Orbigny. Prodr. de Pal., vol. ii, p- 240

Modiola
), p. 218,

1*Char. d. Schicht. u. Petref. des siichs. Kreidegeb.,’ pt. 2 (1840), p. 52, pl. x, fig. 9.
carditoides, Geinitz, ‘Das Elbthalgeb. in Sachsen’ (‘ Palwontographica,’ vol. xx, pt. 1, 1873
pl. xlviii, figs. 1I—13; pl. xlix, figs. 19, 20.

PO

a”

150 CRETACEOUS LAMELLIBRANCHIA.

1873. Cyprina rRApEzoIpALIs, H. B. Geinitz. Das Elbthalgeb. in Sachsen
(Paleontographica, vol. xx,
pt. 1), p. 229, pl. 1, fig. 6

(2 5).
1889. CypricARDIA — E. Holzapfel. Die Mollusk. Aachen. Kreide
(Paleontographica, vol.

XKKV) PLA.

1897. TRapEzIuM TRAPEZOIDALE, H. Woods. Quart. Journ. Geol. Soc., vol. liii, p.
391, pl. xxviii, figs. 9, 10.
1901. CypricarpIA TRAPEzOIDALIS, FY. Sturm. Jahrb. d. k. preussisch. geol.
Landesanst. fiir 1900, vol. xxi,
p. 80, pl. vii, fig. 5.

1902. ae — A. Wollemann. Liimeburg. Kreide (Abhandl.
d. k. preussisch. geol.
Landesanst. N. F., Heft.
37), p. 78, pl. ii, fig. 3;

pl. i, fig. 1.

Description Shell trapezoidal, rounded, inflated. Ventral margin slightly
curved, roughly parallel to the dorsal margin, and passing gradually into the
younded anterior margin. Posterior margin oblique, forming an obtuse angle with
the dorsal margin and an acute angle with the ventral margin. Umbones near the
anterior end, much curved. A sharp, gently curving carina extends from the
wmbo to the posterior angle and cuts off a triangular and slightly concave area.

Ornamentation consists of fine concentric lines.

Measurements :

(1) (2) (3)
Length : F BAS) : 23} . 21 mm.
Height ; ili ; 14. : TAR
Thickness . : 16 : 15 , 1) gs

(1

3) Chalk Rock, Cuckhamsley.

Affinities —Wollemann considers that U'rapezium galicianum (Favre)' is not
distinct from this species, but is founded on an older example than the type of
T. trapezoidale. According to Wollemann, various changes in the form of the
shell take place during growth. Thus, in the older specimens the valves become
more convex, the length relatively less, the posterior margin less oblique, the
ventral margin more curved, the outline less trapezoidal, and the umbones less
curved, This view is probably correct, but none of the English examples which I
have seen pass beyond the stage represented by Romer’s type.

In Trapezium tricavinatum (Rémer)* the umbones are less anterior in position
than in 7’. trapezoidale.

1 * Moll. Foss. de la Craie de Lemberg’ (1869), p. 109, pl. xii, fig. 3.
° «Die Verstein. d. nord-deutsch. Kreidegeb,’ (1841), p. 74, pl. ix, fig. 23.

a)

ISOCARDITA. 151

Remarks.—This species occurs in the Chalk Rock, but is not common. All the
specimens seen are casts, but one shows a fragment of shell.

Type.—The type is stated by Rémer to have come from the Pliner-kalk of
Strehlen (Dresden), but Geinitz says that he has never found the species at that
locality.

Distribution—Chalk Rock of Dover, Cuckhamsley, Aston Rowant, Princes
Risborough, Thickthorn Hill (Bledlow), and Luton railway cutting.

Family—ISOCARDIIDAS, Gray.

Genus—lIsocarpiaA, Lamarck, 1799.
(‘Mém. Soc. Hist. Nat. Paris,’ p. 86.)

Tsocarpia sIMILis, Sowerby, 1826. Text-fig. 25.

1826. TIsocarpr1a situs, J. de C. Sowerby. Min. Conch., vol. vi, p. 27, pl. dxvi,

fig. 1.
1850. — — A. dOrbigny. Prodr. de Pal., vol. ii, p. 163.
1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 204.
1865. a — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p. 240.
1870. . — — F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,

vol. iii, pp. 188, 194.

p Fia. 25.—Isocardia similis, Sowerby. Lower Greensand, near Sandgate. Right valve, and anterior view.
British Museum (Nat. Hist.). The Type. Natural size.

152 CRETACEOUS LAMELLIBRANCHIA.

Description —Shell convex, oval, longer than high. Antero-dorsal margin
short. Anterior margin produced, somewhat pointed, rounded, curving rapidly to
join the slightly convex ventral margin. Posterior margin short, somewhat
truncated. Postero-dorsal margin long, convex, with a considerable ventral slope.
Umbo prominent, recurved. Lunular region deep. A faint carina extends from
the umbo to the postero-ventral extremity. Ornamentation consists of growth-
lines. Length 78mm. Height 70 mm.

Remarks.—The type, a right valve, now in the British Museum, is the only
undoubted example of this species which I have seen. From the nature of the
matrix there seems no doubt that this specimen comes from the mammilatum zone.
The hinge cannot be made out satisfactorily, but the form of the shell agrees
closely with that typical of Isocardia.

Distribution—Lower Greensand (zone of Douvilleiceras mammilatum) near
Sandegate.!

Family—LUCINIDA, Fleming.

Genus—Luctna, J. G. Bruguiére, 1797.
(‘Eneye. Meth., Vers,’ pl. cclxxxiv. Lamarck, ‘Mém. Soe. Hist. Nat. Paris,’ 1799, p. 84.)

Lucina, sp. Plate XXIV, figs. 2, 3.

Internal casts of a Lucina have been obtained from the Spilsby Sandstone
(zone of Belemnites lateralis) of Donnington and Claxby. <A right valve with the
shell preserved was found by Mr. Lamplugh in the Spilsby Sandstone at Holton
and probably belongs to the same species as the casts. The shell bears numerous
small concentric ridges.

.

Lucina, sp. Plate XXIV, figs. 4, 5.

ro) 2

Some internal casts and a portion of an external cast of Lucina have been

' Isocardia? ornata, Forbes, ‘Quart. Journ. Geol. Soc.,’ vol. i (1845), p. 242, pl. ii, fig. 10, is
known only by the imperfect type specimen which is now in the Museum of the Geological Society
(No. 2150), and was obtained from the Lower Greensand of Atherfield. It was referred to Opis by
VOrbigny, ‘ Prodr. de Pal.,’ vol. ii (1850), p. 118.

Tsocardia eryptoceras, VOrbigny, has been recorded by Barrois from the Upper Greensand near
Devizes. See ‘Terrain Crét. supér. de Angleterre et de l’Irlande’ (1876), p. 61.

LUCINA. 153

found in the Lower Greensand! of Blackgang, Shanklin, and Parham Park. The
outline is nearly circular and the convexity small or moderate. The ornamenta-
tion consists of concentric ribs and flat interspaces.

Lucina, sp. Plate XXIV, fig. 6.

A specimen with the two valves united was obtained by the late C. J. A.
Meyer from the Lower Greensand (Ferruginous Sands) of Shanklin, and appears
to belong to a distinct species. The shell is regularly convex, slightly higher than
long, and the lunule is deeply depressed. The ornamentation consists of numerous,
small, regular, concentric ribs.

Lucia P scutpeta, Phillips, 1829. Plate XXIV, figs. 7—9.

1829. Lucina scunpra, J. Phillips. Geol. Yorks., pp. 122, 170, pl. ui, fig. 15
(p. 252, ed. 3).

1844. — — A. @Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 118,
pl. eelxxxiii, figs. 1—4.
1850. _ “= E. Wichwald. Zeitschr. d. deutsch. geol. Gesellsch.,

vol. i, p. 471.

A. dOrbigny. Prodr. de Pal., vol. ii, p. 118.
1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 208.
1862. — os J. G. Chenu. Man. de Conchyl., vol. ii, p. 119, fig. 571.
1866. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p: 291.
1871. _- — F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. ii, p. 252.
1906. — — A. Wollemann. Die Biv. u. Gastrop. norddeutsch. Gaults,

p: 277.

Description—Shell very convex, higher than long, with angular outline.
Antero-dorsal margin long, concave. Postero-dorsal margin long, convex. Angles
oceur at the ventral limit of the lunule, at the junction of the anterior and ventral
margins, near the posterior part of the ventral margin, and at the ventral limit
and the middle of the escutcheon. Umbones high, prominent, sharp, curved

1 Lucina arduennensis, V’Orbigny, and L. Dupiniana, d’Orbigny, have been recorded by Topley
from the Lower Greensand of the Weald. I have not seen any specimens which could be identified
with those species. Two imperfect left valves from the Lower Greensand of Atherfield, now in the
Museum of the Geological Society, were referred by Forbes to L. globiformis, Leymerie. Without
better specimens it is difficult to determine the genus to which Forbes’ specimens belong. See Forbes,
“Quart. Journ. Geol. Soe.,’ vol. i. (1845), p. 240; Leymerie, ‘Mém. Soc. géol. de France,’ vol. y
(1842), p. 4, pl. iii, fig. 8.

154 CRETACEOUS LAMELLIBRANCHIA.

anteriorly. Ridges extend from the umbo to the angles at the margin of the
valve; the parts between the ridges are flattened. Lunule large, ovate, divided
into an inner and an outer part by a ridge. Escutcheon very large, consisting of
a median lanceolate part which is much depressed and separated by a sharp edge
from a large concave outer portion.

Ornamentation consists of broad concentric ridges which run parallel to the
margin of the valve and end abruptly at the Iunule and escutcheon. Very fine,
sometimes indistinct, ribs occur on the ridges and interspaces.

Affinities—Lucina sculpta is quite unlike any other Cretaceous species. Its
angular outline and large concave escutcheon give it an unusual appearance.
Externally it shows some resemblance to some species of Thyasira,’ but the hinge
and adductor impressions are at present unknown. Stoliczka regarded it as
probably a true Lucina.

Remarks.—I have seen only four specimens, of which three are in the British
Museum and one is in the Museum of Practical Geology.

T'ype.—The type cannot be found. It is stated to have come from the Speeton
Clay (? zone of Belemnites minimus).

Distribution.—Lower Gault (Bed vi) of Folkestone.

Luctna tenpra (Sowerby), 1836. Plate XXIV, figs. 10O—14.

1836. Venus? tenera, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp. 114,
335, pl. xi, fig. 7.
1854. = — J. Morris. Cat. Brit. Foss., ed. 2, p. 231.
1865. —- — (2? Lucrna), F. J. Pictet and G. Campiche. Foss. Terr.
Crét. Ste. Croix (Matér.
Pal. Suisse, ser.4), p.189.

1870. - - (2? Caryarts), F. StoWiezka. Paleeont. Indica, Cret. Fauna
8S. India, vol. iii, p. 160.
1875. Lucrna — A.J. Jukes-Browne. Quart. Journ. Geol. Soc., vol. xxxi, p.

300, pl. xv, figs. 10—12.

Description—Shell oval, moderately convex, longer than high, inequilateral,
the anterior part longer and higher than the posterior part. Anterior margin
regularly rounded, passing gradually into the curved ventral margim. Posterior
margin somewhat truncated, forming an obtuse angle with the postero-dorsal
margin. Umbones of moderate size with a slight forward curvature. Lunule
elongate, depressed, limited by a carina. Escutcheon large, not distinctly limited.

1 Avinus, Sowerby ; Cryptodon, Turton.

LUCINA. Ld5

Ornamentation consists of numerous, recular, strong, concentric ribs which become
smaller near the antero-dorsal and postero-dorsal margins.
Measurements :

Q) (2) (3) (4) (5)
Length . 15 : 1 : is! : W385) 9 mm.
Height . 14 5 12 : 1] 11 ; (ay ey
Thickness 8 : 7 ; 6:5 . — 45,

(1—5) Gault, Folkestone.

Affinities.—In form and ornamentation this species resembles L. Sancte-Crucis,
Pictet and Campiche,’ but is much smaller and relatively longer.

Type-—The type came from the Gault of Folkestone, but cannot now be
found. The specimens figured by Jukes-Browne are in the Sedgwick Museum,
Cambridge.

Distribution—Gault of Folkestone and Black Ven. Cambridge Greensand.
Upper Greensand (zone of Schlanbachia rostrata) of Devizes.

Lucina Downes!, sp. nov. Plate XXIV, figs. 15 a—e.

Description.—Shell oval or nearly orbicular, moderately convex, slightly inequi-
lateral, longer than high, postero-dorsal part compressed. Anterior and ventral
margins rounded. Posterior margin less convex than the anterior, forming an
obtuse angle with the convex postero-dorsal margin. Umbones of moderate size.
Lunule elongate. Ornamentation consists of numerous regular, concentric, lamellar
ribs separated by broad, flat interspaces with fine concentric ribs.

Measurements :

(1) (2)
Length 32 26 mm.
Height A D825 DAN
Thickness . 14 ; ee

(1, 2) Blackdown.
Affinities —This species resembles L. Cornueliana, dOrbigny,’ from the
Neocomian, but the umbones are less prominent and the shell is less inequilateral.
It is also similar to DL. subnumismalis, d’Orbigny,’ from the Aachen Greensand,

but the ribs are more numerous and the antero-dorsal margin has a greater

1“ Terr. Crét. Ste. Croix” (‘ Matér. Pal. Suisse,’ ser. 4, 1866), p. 289, pl. exxii, fig. 8.

2 «Pal. Franc. Terr. Cret.,’ vol. iii (1844), p. 116, pl. celxxxi, figs. 3—9.

8 Holzapfel, “Die Mollusk. Aachen. Kreide”’ (* Paleontographica,’ vol. xxxv, 1889), p. 187,
pl. xix. figs. 1—3. Ravn, ‘Mollusk. i Danmarks Kridtafl. I. Lamellibr.’ (1902), p. 129, pl. iv,

fig. 21.

156 CRETACEOUS LAMELLIBRANCHIA.

ve

©

ventral slope. he ribs are more numerous than in Lucina Nereis, @Orbign
from the Cenomanian.
Distribution.—vU pper Greensand (zone of Schlaubachia rostrata) of Blackdown.

Upper Greensand near Lyme Regis.

Lucia visum, Sowerby, 1836. Plate XXIV, figs. 16—19.

1836. Lucrna pisum, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp. 241,
341, pl. xvi, fig. 14.

1850. - — A. dOrbigny. Prodr. de Pal., vol. ii, p. 162.
1854. — = J. Morris. Cat. Brit. Foss., ed. 2, p. 208.
1871. — F. Stoliczka. Paleeont. Indica, Cret. Fauna 8. India, vol.

iii, p. 252.

Non 1844. - A. d@Orbigny. Pal. Franc. Terr. Crcét., vol. ui, pl. celxxxi,
figs. 3—5 (L. Cornueliana, p. 116).
ry —1868. - A. Briart and F. L. Cornet. Meule de Bracquegnies (Mém.

cour. et Mém. des Sav. ctrangers, vol.
xxxiv), p. 69, pl. vil, figs. 18—21.

Description.—Shell small, very convex, with nearly circular outline, slightly
inequilateral; length and height nearly equal. Anterior and ventral margins
forming a regular curve; posterior margin slightly truncated, forming an obtuse
angle with the postero-dorsal margm, Umbones rather large. Lunule ovate,
broad, depressed. Escutcheon indistinctly limited. Ornamentation consists of
concentric ribs, with growth-rings at imtervals.

Measurements :

() (2) (3)
Length : 5 ; Aed : 4 mm.
Height 4°9 : 45 : Ar ys
Thickness. BS ! 3 : DRO a3

(1—3) Blackdown.

Remarks.—The form referred to L. pisum by Briart and Cornet is much larger
than the English examples of that species, and also differs in its relatively longer
and more compressed shell.

T'ype.—From Blackdown ; in the Bristol Museum.

Distribution —Upper Greensand (zone of Schlanbachia rostrata) of Blackdown.

1*Prodr. de Pal.,’ vol. ii (1850), p. 162. Guéranger, ‘Album Paléont. de la Sarthe’ (1867),
p. 12, pl. xv, fig. 15. The hinge figured by Guéranger does not agree with Lucina. Stoliczka suggests
that this species belongs to Cyprimeria, see ‘ Paleont. Indica, Cret. Fauna §. India’ (1871),

pp. 164, 253.

SPHARA. 157

Family—CORBID AN, Dall.

-Genus—Corsicenta, J. Morris and J. Lycett, 1853.
(‘Moll. Great Ool.,’ pt. ii, p. 94.)

CoRBICELLA CLAXBIENSIS, sp. nov. Plate XXIV, figs. 20—23.

Deseription.—Shell oval, regularly convex, slightly inequilateral, anterior part
rather larger than the posterior part, length equal to nearly 12 times the heieht.
Anterior margin rounded. Ventral margin convex, curving rapidly to join the pos-
terior margin which forms an angle with the nearly straight postero-dorsal margin.
Umbones broad, inconspicuous, scarcely curved, close together. Surface of shell
smooth except for growth-lines.

Measurements :

(1) (2) (3) (4)
Length ; 38 . 37 p 30 ‘ Oe Savahane
Height f 26 25 : 21 : nS ae

(1—4) Claxby Ironstone, Benniworth Haven.

Remarks.—The genus Corbicella does not appear to have been recognised in
deposits of Cretaceous age, but since it is present in the Portlandian its occurrence
in the lower part of the Speeton Series of Lincolnshire causes no surprise.

C. claxbiensis is similar in outline to some forms of CU. Pellati, de Loriol,' from
the Portlandian.

Type.—In the Sedgwick Museum, Cambridge.
Distribution.—Spilsby Sandstone (zone of Belemnites lateralis) of Claxby and
Donnington. Claxby Ironstone (zone of B. lateralis) of Benniworth Haven.

Genus—Sruamra, J. Sowerby, 1822.
(*Min. Conch.,’ vol. iv, p. 41.)

SPH#RA corrvucata, Sowerby, 1822. Plate XXIV, fig. 24; Plate XXV, figs. 1, 2;
text-fig. 26.

1822. Spumra corrvaara, J. Sowerby. Min. Conch., vol. iv, p. 42, pl. ceexxxy.
»

1842. Venus corprrormis, A. Leymerie. Mém. Soe. géol. de France, ser. 2, vol.
Vv, p- ay pl. We fig. 5.

im ae ae ’ =e ed stirs °
1 De Loriol and Pellat, ‘ Jurass. de Boulogne-sur-mer’ (1875), p. 67, pl. xiv, fig. 12.

21

| =

158 CRETACEOUS LAMELLIBRANCHIA.

1842. Carprum GALLoprovincraLE, P. Matheron. Catal. Foss. du Départ. des
Bouches-du-Rhone, p. 155,
pl. xvii, figs. 1, 2.
1844. Corsis corpirormis, A. d’Orbigny. Pal. Frane. Terr. Crét., vol. iii, p. 111,
pl. cclxxix.

1845. — corruGcata, HZ. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 239.

1850. — a @’Orbigny. Prodr. de Pal., vol. ii, p. 78.

1854. Sprara — J. Morris. Cat. Brit. Foss., ed. 2, p. 224.

1855. Corpis — G. Cotteau. Moll. Foss. de l’Yonne, p. 80.

1856. _- — FJ. Pictet and EB. Renevier. Foss. Terr. Aptien (Matér.
Pal. Suisse, ser. 1), p. 76, pl. viii,
fig. 3.

1859. — corpirormis, J. Vilanova-y-Piera. Mem. geog.-agric. de Castellon,

pl. iii, fig. 13.
1865. — corrvaata, H. Coquand. Mon. Aptien de l’Hspagne, p. 116.
1866. Frpria — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse,
ser. 4), p. 279.
1869. Patmocorsis corpirormis, 7’. A. Conrad. Amer. Journ. Conch., vol. v,
p- 101.
1871. Spnuara corruaeata, F. Stoliczka. Paleont. Indica, Cret. Fauna S. India,
vol, i, pp. 247, 252.
? 1877. Corsts cf. corrueata, G. Bihm. Zeitschr. d. deutsch. geol. Gesellsch., vol.
xxix, p. 240.

1897. — corruaata, K. Gerhardt. Neues Jahrb. fiir Min., ete., Beil.-Bd. xi,
p. 186.
1899. Fimpria — A. Wollemann. Zeitschr. der deutsch. geol. Gesellsch.,

vol. li, p. 592.

Description—Shell large, stout, inflated, subglobular, shghtly inequilateral,
height and length nearly equal. Anterior margin rounded, forming an angle with the
hinge-margin, and passing gradually into the ventral margin with which it forms
a regular curve. The ventral margin curves rapidly towards the posterior margin,
which makes an obtuse angle with the hinge-margin. Lunule flattened or depressed,
with a swollen lower margin which is separated from the rest of the valve by a
furrow. Escutcheon triangular, limited by a furrow which passes from the umbo
to the posterior margin. Umbones large, prominent, curved anteriorly. Ornamen-
tation consists of broad, strong, unequal, concentric ridges which are more numerous
on the middle than on the anterior and posterior parts of the shell. The concentric
ridges are crossed by numerous, small, radial ribs.

Measurements :

(1) (2) (3) (4)
Length 95 : 84 : 80 : 70 mm.
Height 93 ; 83 : ath ; 66

(1—4.) Lower Greensand, Atherfield.

SPHARA. 159

Remarks.—This species is the type of the genus Sphewra. It is fairly common

in the Perna-bed of the Isle of Wight. A young example is figured by d’Orbigny.

Type—The type was obtained by Professor Sedewick from the Peria-bed of
Sandown, but cannot now be found.
>

Fig. 26.—Sphera corrugata, Sow. Lower Greensand, near Hythe. Museum of Practical Geology,
No. 19716. Dorsal view, x +.

Distribution.—Lower Greensand (Perna-bed and Crackers) of Atherfield; also
recorded by Fitton from Beds viii and xiy. Hythe Beds of Hythe and Maidstone.
Recorded by Topley from the Atherfield Beds of Peasmarsh and Shalford; the
Hythe Beds of Lympe; and the Sandgate Beds of Sandgate.’

Sruzra, sp. Plate XXV, fig. 3.

A small specimen from the Chalk Marl of Chard appears to belong to a distinct
species. It is much smaller than S. corrugata, also relatively longer, more oval in
outline, and less inflated. The escutcheon is not defined, the lunule is small or
absent, and the antero-dorsal margins are thick and prominent. The concentric
ridges resemble those of S. corrugata, but the radial ribs are more distinct. Length
16°5 mm. ; height 14 mm.; thickness 12°5 mm.

1The type of Corbis? jfibrosa, Forbes, from Peasmarsh, is in the Museum of the Geological
Society (R 2154), but is too imperfect for determination. Forbes, ‘Quart. Journ, Geol. Soc.,’ vol. i

(1845), p. 239.

160 CRETACEOUS LAMELLIBRANCHIA.

Genus—MUTIELLA, Stoliczka, 1871.
(‘ Palewont. Indica, Cret. Fauna §. India,’ p. 247.)

Morieita ? caANALIcuLATA (Sowerby), 1836. Plate XXV, figs. 4—6.
1836. Perrrcona canauicuLara, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol.
iv, pp. 24], 341, pl. xvi,
fig. 11.
—- -- nuciForMis, Sowerby. Ibid., pp. 241, 341, pl. xvi, fig. 10.
1850. Carprum cananicuLatum, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 163.
= = NucIFoRME, d’Orbigny. Ibid., p. 163.
1854. Prrricona? cananicunara, J. Morris. Cat. Brit. Foss., ed. 2, p. 220.
—_— Nucirormis, Morris. Ibid., p. 220.
1866. Carprum canauicunatum, F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal.
Suisse, ser. 4), p. 270.
1865-66. Prrricona nucrrormis, Pictet and Campiche. Ibid., pp. 163, 276.
1870. -- CANALICULATA (CARpIuUM), F’. Stoliczka. Palawont. Indica,
Cret. Fauna 8. India, vol.
iii, p. 141.
-- -- NucIFoRMIs (? Corsis), Stoliczka. Ibid., p. 141.

Description.—Shell inflated, outline more or less orbicular, inequilateral, length
and height equal. Margins rounded. Anterior margin less convex than the pos-
terior margin. The latter makes an obtuse angle with postero-dorsal margin and
curves rapidly to join the ventral margin. The margin in front of the umbo
expands. Umbones large, contiguous, curving inward and forward. No lunule.

Ornamentation consists of numerous, regular, radial ribs, separated by narrow
furrows, and crossed by narrow concentric ridges which are more prominent
on the posterior part of the shell than elsewhere. Inner margins of the valves
crenulate.

There are two cardinal teeth in the left valve and one in the right. Behind
the umbo a long, nearly straight, sharp ridge forms the inner margin of the
ligament groove.

Measurements :

(1) (2) (3) (4)
Length : 205. « 19 Sav 3 7 ito 2 oemm-
Height : 20°5 oi ALO! ah eA eda ee Obes

(1—4) Blackdown.
Affinities —Vhe generic position of this species has been for a long time a
matter of doubt, but no one appears to have accepted Sowerby’s view. ‘The

MUTIELLA. 161

species is rare, and the opinions expressed by various authors appear to have been
based entirely on the figures given by Sowerby.

The hinge is similar to that of Mutiella coarctata (Zittel),' but shows some points
of difference: thus the transverse corrugations or teeth on the expanded anterior
margin appear to be absent, and the terminal posterior lateral tooth cannot be
recognised with certainty. The points of resemblance, however, and the similarity
in the form of the shell and the character of the ornamentation seem sufficient
to justify the assignment of this species either to Mutiella or to a closely
alhed genus.

From the figures given by Sowerby, Petricola nucifornis appears to differ con-
siderably from P. canaliculuta, but after an examination of the type of the former
I am led to the conclusion that it is not specifically distinct from the latter ; it
differs only in being more inequilateral, and the apparent difference in the orna-
mentation is due to the imperfect preservation of the surface of the shell in
P. iueifornis.

Types —From Blackdown. The type of Petricola canaliculata cannot be found.
The type of P. nuciformis is in the Bristol Museum.

Distribution.—Upper Greensand (zone of Schlaubachia rostrata) of Blackdown,
and Peak Hill, near Sidmouth.

Morrenta rorunpara (2 Orbigny), 1844.

1844. Corsis rorunpara, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. in, p. 113,
pl. celxxx, figs. 1-4.

1850. — — a Prodr. de Pal., vol. ii, p. 162.

1867. _ — E. Guéranger. Album Paldéont. de la Sarthe, p. 15,
pl. xix, figs. 10, 11.

1870. — — FI’. Rimer. Geol. v. Oberschles., p. 340.

1871. Murietxa rorunpara, I’. Stoliczka. Palwont. Indica, Cret Fauna 8. India,
vol. iii, pp. 247, 252.
1896. Corrs rorunpara, A. J. Jukes-Browne and W. Hill. Quart. Journ. Geol.

Soe., vol. lii, p. 153.

A portion of a right valve of Mutiella rotundata from the Cenomanian (Bed 11)
of Dunscombe, South Devon, was found and determined by the late C. J. A.
Meyer. An internal cast was collected from Bed 10 of Beer Head by Mr. Jukes-
Browne, who also records the species from the Chloritic Marl of Maiden Bradley,
1 Fimbria coarctata, Zittel, ‘Die Biv. d. Gosaugeb.,’ pt. i (1864), p. 44, pl. vii, fig. 5. Referred by
Stoliczka, and subsequently by Zittel and by G. Miiller, to the genus Mutiella, Compare also the

hinge of Mutiella rotundata figured by Guéranger, ‘Album Paléont. de la Sarthe’ (1867), pl. xix,

fig. 11.

162 CRETACEOUS LAMELLIBRANCHIA.

and the Chalk Marl of Chard. The specimens seen are not sufficiently perfect for
figuring.

M. votundata is the type of the genus Mutiella. In France this species is found
in the Cenomanian of Le Mans, Sarthe, Rouen, ete.!

Family—UNICARDIIDA, Fischer.

Genus—Unicarpium, A. d’ Orbigny, 1849.
(‘Prodr. de Pal.,’ vol. i, p. 218.)

UNICARDIUM CLAXBIENSE, sp. nov. Plate XXV, figs. 7 a, b.

Description.—Shell large, oval, inflated, with somewhat flattened sides, very
inequilateral; anterior part much longer than posterior part. Anterior margin
well rounded, passing gradually into the antero-dorsal margin, and into the ventral
margin, which is only slightly curved. Posterior margin truncated. Umbones
broad, curved inward and slightly forward. In front of the umbones the shell is
depressed.

Ornamentation consists of narrow, sharp, prominent, somewhat irregular con-
centric ribs separated by relatively broad, concave interspaces.

Measurements :

(1) (2)
Length . ; 52 ; 40 mm.
Height ; 45 : a4,

(1, 2) Benniworth Haven.

Affinities.—In this species the umbones are not so high and the posterior part
of the shell is longer than in U. heteroclitum (dOrbigny)*; also the ribs appear to
be narrow and sharper.

Type.—In the Sedgwick Museum, Cambridge.

Distribution—Claxby Ironstone (zone of Belenmnites lateralis) of Benniworth

Haven, Lincolnshire.

1 Corbis? Morisoni, Woods, from the Chalk Rock of Cuckhamsley, is at present known by two
imperfect valves only. The hinge cannot be seen, and the generic position of the species is still
uncertain. See Woods, ‘Quart. Journ. Geol. Soc.,’ vol. liii, p. 392, pl. xxviii, figs. 13, 14.

2 In Murchison, de Verneuil and de Keyserling, ‘Géol. Russie de l'Europe,’ vol. ii (1845), p. 460,
pl. xxxix, figs. 9,10. D’Orbigny, ‘ Prodr. de Pal.,’ vol. 1 (1849), p. 367. BHichwald, ‘ Lethwa Rossica,’
vol. ii (1868), p. 647. Two examples of U. heteroclitum from the Lower Volgian, near Moscow, are in

Mr. Lamplugh’s collection.

UNICARDIUM. 163

UNIcAaRDIUM VECTENSE, sp. nov. Plate. XXV, figs. 8—11.

Deseription.—Shell thin, much inflated, oval or slightly subquadrate, imequi-
lateral, the anterior part rather larger than the posterior part; length a little
greater than height. Antero-dorsal margin short, nearly straight. Anterior
margin rounded, making an obtuse angle with the antero-dorsal margin, and
curving rapidly to join the moderately convex ventral margin. Posterior margin
rounded, slightly truncated. Postero-dorsal margin slightly convex. Umbones
prominent, contiguous, curving inward and forward. Ornamentation consists of
numerous, strong, somewhat irregular, concentric ribs. Ligament in a long,
narrow groove. ‘Teeth absent or poorly developed.

Measurements :

(1) (2) (3) (4)
Length . 20 : 18 ; 16 : 2mm
Height . 19 : 17) 15 : (NIG

(1—4) Crackers, Atherfield.
Affinities.—The shell is relatively higher, the umbones more prominent, and
the ribs rather stronger than in UV. Hbrayi, de Loriol.'
Distribution Lower Greensand: Crackers of Atherfield, Perna-bed of Sandown,
and Ferruginous Sands of Shanklin.

Unicarpium, sp. Plate XXV, fig. 12.

A specimen of Unicardium from the Upper Greensand of South Deyon* was
collected by Sir H. T. De la Beche and is now in the Museum of the Geological
Society, No. 1580. It resembles U. vectense, but the umbones are not so promi-
nent and the ribs are smaller, more numerous, and more regular.

Unicarpium ? Gaurtinum (Pictet and Roux), 1852.

1852. Corpis aauttina, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de
Genéve, p. 448, pl. xxxiv, fig. 4.

1866. Fimprra — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse, ser. 4),

p. 282, pl. exxii, figs. 3, 4.

1871. — — F. Stoliczka. Palswont. Indica, Cret. Fauna 8. India,
vol. ili, p. 252.
1875. Corsts -- A. J. Jukes-Browne. Quart. Journ. Geol. Soc., vol. xxxi,

p. 300, pl. xv, fig. 9.

1 «Gault de Cosne’ (1882), p. 70, pl. viii, figs. 13-16.
2 Probably from near Sidmouth or Blackdown.

164 CRETACEOUS LAMELLIBRANCHIA.

Two internal casts from the Cambridge Greensand (derived from the Gault)
were identified by Mr. Jukes-Browne as Corbis gaultina, Pictet and Roux. The
specimens are in the Sedgwick Museum, and no other examples appear to have
been found. The type of C. gaultina came from the Gault of Saxonet. In
external form this species agrees closely with Unicardium, but the hinge is
unknown, so that the generic position cannot be determined with certainty.

UNICARDIUM RINGMERIENSE (Mantell), 1822. Plate XXV, figs. 13, 14.

1822. Venus? rrnamertensis, G. Mantell. Foss. S. Downs, p. 126, pl. xxv, fig. 5.
1850. Panopma — A. d’Orbigny. Prodr. de Pal., vol. ii, p. 157.
1854. Unicarprum rinemenienss, J. Morris. Cat. Brit. Foss., ed. 2, p. 229.
1865, Carpium — FJ. Pictet and G. Campiche. Foss. Terr. Crét.

Ste. Croix (Matér. Pal. Suisse,
ser. 4), p. 195.
Non 1850. Arca rrnemerensts, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in
Deutschland, p. 162.
— 1872. Murieiia rrnemerensis, //. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal-
wontographica, vol. xx, pt. 2),
p. 61, pl. xvi, figs. 11-13.
1877. — = A. Fritsch. Stud. im Gebiete der bohm. Kreide-
format. II Weissenberg. u. Malnitz.
Schicht., p. 115, fig. 75.

— 1883. _ — Fritsch. bid. III Iserschicht., p. 100, fig. 64:
— 1889. — — Fritsch. Ibid. IV Teplitz. Schicht., p. 78.
— 1897. — _ Fritsch. Tbid. VI Chlomek. Schicht., p. 54, fig. 59.

Description.—Shell subquadrate, rounded, inflated, antero-dorsal part com-
pressed, length rather greater than height, inequilateral, anterior part larger than
the posterior part. Antero-dorsal margin nearly straight. Anterior margin
moderately convex, making an obtuse angle with the antero-dorsal margin and
curving rapidly near the ventral margin. The latter is moderately convex and
curves upward to join the posterior margin, which is slightly curved, and forms
an obtuse angle with the postero-dorsal margin. Umbones large, prominent,
contiguous, curving forward. Ornamentation consists of strong, narrow, con-
centric ridges.

Measurements :

Q) (2)
Leneth . : , 42 ; ; 36 mm.
Height. . 38 : 34 ,,

(1) Chalk Marl, Titherleigh.
(2) Chalk Marl, Chardstock.

THETIRONTA. 165

Ttemarks.—The specimens from the Pliner-kalk of Strehlen which were
referred to this species by Geinitz appear to be related to Mutiella coarctata
(Zittel).!

Type.—The type came from the Chalk Marl of Middleham, but cannot now be
found.

Distribution.—Upper Greensand (zone of Schlenbachia rostrata) of Devizes.
Base of Chalk Marl of Titherleigh and Chardstock. Chalk Marl of Middleham
and Ringmer.

[Systematic position not determined. |

Genus—Tuerironta, . Stoliczka, 1870.

(‘ Paleont. Indica, Cret. Fauna 8. India,’ vol. iii, p.158. Thetis, J. de C. Sowerby, ‘ Min. Conch..,’
vol. vi, 1826, p. 19. Non Thetis, Oken, 1815. Syn. Fimbriella, Stoliezka, op. cit., p. 246.)

The genus Thetironia [Thetis] has been placed in the family Veneride by
Deshayes, d’Orbigny, Chenu, Stoliczka, Zittel, Fischer, Dall, and other authors, on
account of the presence of the acutely angular line which has often been regarded
as a pallial sinus. This angular line appears as a deep groove on internal casts,
and must consequently have been a prominent rib on the interior of the shell. In
its position and rib-like form it is quite unlike the pallial sinus of any lamellibranch,”
and it seems to be a structure of an entirely different nature, probably serving, as was
suggested by S. P. Woodward * merely to strengthen the thin shell. Thetironiu is
further distinguished from the Veneride by its hinge, which is of quite a different
type (see Plate XXVI, figs. 10, 14). Stoliezka, in referring this genus to the
Veneride and sub-family Dosiniine, says: “There can be little doubt
that all the external characters indicate a close appproach to the recent
Olementia ”; the hinge, however, which seems to have been unknown to Stoliczka,
shows that this view of the relationship of Thetironia cannot be maintained.

A concentric ridge seen near the ventral margin on some internal casts of
Thetironia has been regarded by some authors as evidence of a simple pallial line ;
but the presence in some specimens of several similar ridges at different distances
from the margin suggests that they are really of the nature of growth-rings (see
Plate XXVI, fig. 6).

Thetironia was identified with Poromya by S. P. Woodward (1854) and by Hi:

1 G. Miller, ‘ Mollusk. Untersen. v. Braunschweig u. Ilsede’ (1898), p. 60.

2 De Loriol compared it with Lucinopsis, but the differences between the pallial sinus of that genus

and the angular rib of Thetironia are considerable.
3 “Manual of the Mollusca,’ ed. 1 (1854), p. 319; ed. 3 (1875), p. 491. Woodward says,

“umbones strengthened inside by a posterior lamina.”
oO.

166 CRETACEOUS LAMELLIBRANCHIA.

and A. Adams (1858). Deshayes (1858), and Pictet and Campiche (1865),
though considering them allied forms, did not regard them as generically
identical. ‘The latter authors had little confidence in the suggested relationship of
Thetironia to Venus, but in the absence of specimens furnishing decisive evidence
they.Jeft the former genus in the family Veneridz. In its external form and thin
shell Thetironia shows some resemblance to Poromya, but the conspicuous internal
ligament found in the latter is absent in the former.

In a systematic list of Mollusca, J. E. Gray! placed Thetironia in the Lucinide,
but gave no reasons for assigning it to that family. Although elongate markings
do occur in the interior of some species of Lucina, they show but little resemblance
tothe angular rib of Thetironia. Further, the hinge is unlike that typical of Lucina ;
for although in some few species (e.g. L. gibba, L. pennsylvanica) in which the
umbones have a considerable anterior curvature, the positions of the cardinal teeth
become somewhat similar to those in T'hetironia, yet this is clearly a secondary
character due to torsion and cannot be taken as evidence of any affinity between
Lucina and Thetironia.

The hinge in some of the Corbide, such as Spheriola, Gonodon, and Mutiella
resembles that of /'hetironia, but is far stouter, and the shell is much thicker. The
hinge in Unicardium also is somewhat similar to that of U'hetironia, since lateral
teeth are absent, but the cardinals are less developed. Unicardium, however,
differs from Thetivonia in the character of its ornamentation and in the form of
the shell.

In both form and position the teeth of T'hetironia show a striking resemblance
to the cardinal teeth of the Cardiidee (especially to Protocardia), and the hinge-
margin in front of the umbo expands in a similar way ; some further resemblance
is seen in the position and prominence of the external ligament, and in the general
form of the shell, which is similar to that of the nearly smooth Cardium (Serripes)
grenlandicum, Chemnitz. The greater development of ornamentation on the
posterior part than on the remainder of the shell in Thetironia is also suggestive
of some forms of Protocardia. The position of the cardinal teeth in the Cardiide
is practically constant and is a character of systematic importance ; so that the
close resemblance between these teeth in Thetivonia and in the Cardide seems to
indicate a real relationship. Opposed to this, however, is the absence of lateral
teeth*® in Thetironia; but although these teeth are usually found in the Cardidee,

1 «Synopsis Brit. Mus.,’ ed. 44 (1842), p. 91.

2 Although @Orbigny placed Thetironia m the Veneride, he recognised that in some respects it
clearly resembles Cardium. See ‘ Pal. France. Terr. Crét.,’ vol. iti (1846), p. 451.

8 Inthe ‘ Additions and Corrections’ to his Monograph Stoliczka states that in Thetironia igqnobilis
there are two cardinals and a minute posterior lateral in the right valve, and three cardinals in the
left valve. ‘ Palaont. Indica, Cret. Fauna 8. Indica’ (1871), p. 485.

THETIRONIA. 167

yet they are occasionally absent. Other differences are seen in the very thin and
punctate shell, and in the internal rib.

Nothing closely resembling the internal rib of Thetironia seems to be known in
any other lamellibranch. But in some Jurassic and Cretaceous! species of Proto-
cardia a rib, either single or A-shaped, is found at the inner boundary of the
posterior area; this, however, differs from the rib of Thelironia, in that it reaches
the margin of the valve and is not continued anteriorly to the neighbourhood of
the anterior adductor.

It seems, therefore, that although Thetironia resembles the Cardiide in several
respects, yet the points of difference are too great to allow of its being included in
that family.

-TuETIRONIA MINOR (Sowerby), 1826. Plate XXV, figs. 15a—c; Plate XXVI,
1

figs. 1—8.

1822. Venus, G. Mantell. Foss. 8. Downs, p. 73.
1826. Tueris minor, J. de C. Sowerby. Min. Conch., vol. vi, p. 21, pl. dxiii,
figs. 6 (2 5).
1829. —— — M.J.L. Defrance. Dict. Sci. Nat., vol. liv, p. 275.
1841. — Sowers, I’. A. Romer. Die Verstein. d. nord-deutsch. Kreidegeb.
p. 72 (partim).
1845. = — var. a minor, var. 8. major. HE. Forbes. Quart. Journ.
Geol. Soc., vol. i, p. 242.
1846. — uamvicara, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. ili, p. 452,
pl. eeelxxxvu, figs. 1—3.
1832-53. — minor, G. P. Deshayes. Traité Elément. Conchyl., vol. i, p. 575,
pl. xxui, figs. 3, 4.
1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 227.
— —- S. P. Woodward. Manual of the Mollusca, fig. 221 (on
p- 318).
1865. — — F.J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser. 4),
p- 202, pl. exii, fig. 4.
1870. — uazxvicara, Pictet and Campiche. Tbid., p. 203, pl. exii, figs. 2, 3.

— ‘THerrronrs minor, F’. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. iii, p. 158.

1884. T'netis minor, O. Weerth. Die Fauna des Neocom. im Teutoburg. Walde
(Paleont. Abhandl., vol. ii), p. 41, pl. ix,

figs, 5, 6.
1898. — umvieata, EL. G. Skeat and V. Madsen. Jur. Neoc. and Gault
Boulders in Denmark,
p- 176, pl. vi, figs. 7—9.
1 Part of this rib is seen in a figure given by Pictet and Campiche, ‘'Terr. Crét. Ste. Croix’

(‘“ Matér. Pal. Suisse,” ser. 4, 1866), pl. exxi, fig. 7a.

168 CRETACEOUS LAMELLIBRANCHIA.

1895. Tueris minor, I’. Vogel. Holliindisch. Kreide, p. 58.
1900 — — A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. holland.
Neocoms, p. 118.

Non 1846. — — A.dOrbigny. Pal. Frang. Terr. Crét., vol. ii, p. 453, pl.
ceclxxxvui, figs. 4—7.

— 1850. — — dOrbigny. Prodr. de Pal., vol. 1, p. 136.

— 1868. = — EE. v. Hichwald. Lethea Rossica, vol. ii, p. 707, pl. xxvi,
fig. 6.

Description—Shell oval, rounded, convex, slightly (sometimes moderately)
inequilateral; length rather greater than height. Margins forming nearly
regular curves; anterior margin less convex than the posterior, making a rounded
angle where it meets the nearly straight antero-dorsal margin. Umbones promi-
nent, rather broad, close together, more or less curved forward. Lunular region
depressed, not limited. Postero-dorsal region sometimes slightly compressed.

Ornamentation consists of slightly-raised concentric Imes at regular intervals
with less distinct lines between ; and of regular rows of radial pits, which on the
posterior part of the shell are replaced by rows of short spiny projections or
minute tubercles.

A long, acutely angular rib extends from the level of the posterior adductor
to near the umbo. The front part of this rib is continued to near the anterior
adductor, but is less prominent than the angular part; at first it curves ventrally,
and afterwards dorsally, the last part being somewhat angular.

Measurements :

GQ) (@) @) (4) (5) (6) (7) (8) (9) (0) 1)
Length 31 30 27 265 25 28 30 26 20 175 17 mm.
Height 285 29 25 25 24 215 27 235 18 165 16 ,,
(1—6) Crackers, Atherfield.
(7—11) Internal casts, Lower Greensand, Shanklin.

Affinities —Pictet and Campiche separated, but with considerable hesita-
tion, the examples of Thetirvonia found in the Crackers of Atherfield from
those found in the Ierruginous Rock of Shanklin. he former they referred to
1’. levigata, VOrbigny (won Sowerby) ; whilst the latter are typical of 7. minor.
There is, as stated by those authors, considerable difficulty in comparing
specimens from the two localities owing to their different states of preserva-
tion. Those from Atherfield have the shell well preserved in nearly all
cases, although not uncommonly the original form has been somewhat modified
by crushing. ‘The specimens from Shanklin, on the other hand, are nearly always
sasts, but owing to the hardness of the rock they retain their original form
more perfectly.

Pictet and Campiche thought that the Atherfield form was less convex and

THETIRONIA. 169

more inequilateral than the Shanklin form. After comparing a considerable number
of specimens I find that those from Atherfield are, as a rule, slightly less convex ;
but the more inequilateral character is not constant; specimens of the same size
are commonly quite as nearly equilateral, but the inequilateral character becomes
more marked with age. Since larger forms are more common at Atherfield than
at Shanklin, one may at first sight get the impression that there is a real difference
in the mequilateral character. I have not seen any specimen from Atherfield so
inequilateral as the form figured by Pictet and Campiche appears to be, and I think
it is probable that their specimen was somewhat distorted by crushing.

T. genevensis, Pictet and Roux, is distinguished from 7’. minor by the height and
length being equal, by its more nearly equilateral form, and by a difference in the
curvature of the rib in front of the angular part.

Remarks.—Thetironia has been recorded by Phillips and Judd from the
Speeton Clay, but I have not seen any examples from that deposit. In some
collections from Speeton specimens of Cyprina have been identified as Thetironia.

Type.—F ig. 6, Lower Greensand of Shanklin; in the British Museum. The
original of fig. 5 from near Lyme Regis has not been seen.

Distribution.—Lower Greensand: Crackers of Atherfield; also recorded by
Fitton from the Perna-bed and Beds vi, viii, ix, x, xiii, and xiv between Ather-
field and Blackgang Chine. Ferruginous Sands of Shanklin. Atherfield Beds of
Kast Shalford. Hythe Beds of Hythe. Sandgate Beds of Sandgate, etc. Folke-
stone Beds of Folkestone.

THETIRONIA Lavicara (Sowerby), 1818. Plate XXVI, figs. 9—14.

1818. Corsuna Levicata, J. Sowerby. Min. Conch., vol. iii, p. 14, pl. ceix,
figs. 1, 2.

1826. Tuerris masor, J. de C. Sowerby. Tbid., vol. vi, p. 20, pl. dxiii, figs. 1—4.

1829. _ — M.J.L. Defrance. Dict. Sci. Nat., vol. liv, p. 276.

1850. Unicarpium Lxvicatum, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 163.

1854. Tueris bevieata, J. Morris. Cat. Brit. Foss., ed. 2, p. 227.

a= — mason, Morris. Ibid., ed. 2, p. 227.

2. = — J. G. Chenu. Manuel de Conchyl., vol. ii, p. 90, fig. 405.

1865. — — F.J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser. 4), pp. 20,
210, pl. exii, fig. 5.

1 Pictet and Roux, ‘ Moll. Foss. Gres verts de Gentve’ (1852), p. 420, pl. xxx, fig. 2. Pictet and

Campiche, ‘ Terr. Crét. de Ste. Croix ’ (1865), p. 206, pl. exii, fig. 7. Barrois records T’. geneve nois fre gn
the Upper Greensand of Lulworth, but I have not seen any specimens ; see Barrois, * Terr. Cret. Super.
de l’'Angleterre,’ etc. (1876), p. 90.

170 CRETACEOUS LAMELLIBRANCHIA.

21868. Tueris mason, A. Briart and F. L. Cornet. Meule de Bracquegnies (Mém.
cour. et Mém. des Sav. ¢trangers, vol.
xxxiv), p. 83, pl. vii, figs. 14, 15.
1871. Fimerierita tevieata, F. Stoliczka. Paleont. Indica, Cret. Fauna S.
India, vol. iii, p. 246.
1882. Tueris masor, P. de Loriol. Gault de Cosne, p. 61, pl. viii, figs. 6—8.

? 1874. — -— W. Dames. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxvi,
p. 766, pl. xxi, fig. 4.
1885. — — FF. Nitling. Die Fauna d. baltisch. Cenoman. (Palont.

Abhandl., vol. 11), p. 29, pl. v, fig. 6.

Non 1845. — Sowersir var. 8 Mason, FL. Forbes. Quart. Journ. Geol. Soc., vol. i,
p. 242.
1846. — masor, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 454, vol.

ceclxxxvii, figs. 8—10.

= — tuaevieara, d’Orbiqny. Ibid., vol. iii, p. 452, pl. ecelxxxvii, figs. 1—3.
qny if i $s

=wS50: —_— — @Orbigny. Prodr. de Pal., vol. ui, p. 118.
— — masor, d’Orbigny. Ibid., vol. ii, p. 160.
P— 1852. — Sowersyt, 2. Kner. Denkschr. d. k. Akad. Wissensch. Wien, Math.-
nat. Cl., vol. iii, p. 311, pl. xvi, fig. 21.
? — 1868. — magsor, EH. v. Lichwald. Letheea Rossica, vol. i, p. 708.

Measurements :
© @ @& © (5) (6) (7) (8) (9)
Length... 47 42 41 39 305 29°5 22:5 22 13 mm.
Height . 48 40 39 37 27 28 21 DO Ale as
(1—9) Blackdown.

Ajjinities.—This species is closely allied to 7’. minor, with which it was united
by Romer under the name 7’, Sowerli/, but it possesses relatively higher and
narrower umbones than 1. iminor., T'. levigatu is commonly of larger size than
1’. minor, and as in the case of the latter, the large forms are more inequilateral
than the small forms. A rather small example was figured by Sowerby as Corbula
levigata, and was taken by Stoliczka as the type of a new genus Mimbriella, but it
proves to be, as was suggested by Pictet and Campiche, an example of 7’. major.

The hinge can be seen in some specimens from Blackdown (Plate XXVI, figs.
10, 14). It consists of two small conical or tubercular teeth just below the
umbo of each valve. In the right valve the teeth are placed one above the other,
but the dorsal tooth is shghtly in front of the ventral and rather smaller than the
latter. In the left valve the teeth are side by side, nearly on the same level,
and the anterior tooth is rather larger than the posterior. Lateral teeth are
absent. The external ligament is short and prominent.

T'ypes.—The type of Corbula levigata, from Blackdown, and the types of
Thetis major, from Blackdown and Devizes, are in the British Museum. 1. major
is the type of the genus Thetis, Sowerby.

TELLINA. 171

Distribution —Gault of Black Ven. Upper Greensand (zone of Sehla@iubachia
rostrata) of Blackdown, Potterne, Devizes, and near Lyme Regis. Recorded by
Price from the Gault of Folkestone.

Family—TELLINIDA, Deshayes.

Genus—TerLLINA, Linneus.
(‘ Syst. Nat.,’ ed. 10, 1758, p. 674; ed. 12, 1767, p. 1116.)

Trenmina Carreront, @’Orbigny, 1845. Plate XXVI, figs. 15, 16.

1842. Tenurna ? vel PsAmMosra 2? ANGULATA, Deshayes in A. Leymerie. Mem. Soe.
séeol. de France, vol. v, pp. 3, 24,
pl. iii, fig. 6 (non T. angulata, L.).
1845. — ANGULATA ?, EH. Forbes. Quart. Journ. Geol. Soce., vol. i, p. 239.
— Treiiina Carteront, A. d’Orbigny. Pal. France. Terr. Crét., vol. ii, p. 420,
pl. ccelxxx, figs. 1, 2.

1850. — — @ Orbigny. Prodr. de Pal., vol. ii, p. 75.
1861. -- —- P. de Loriol. Anim. Invert. Foss. Mt. Saltve, p. 59,
pl. vii, fig. 2.
1865. —- — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matc¢r. Pal. Suisse, ser.
4), p. 134.
1870. — — F. Stoliczka. Palseeont. Indica, Cret. Fauna 8. India,
vol. ili, p. 123.
1884. _ — O. Weerth. Die Fauna des Neocom. im Teutoburg.
Walde (Paleont. Abhandl., vol. 11),
p- 41.
1895. _- = G. Maas. Zeitschr. d. deutsch. geol. Gesellsch., vol.
xlvii, p. 257.
1900. —- ~- A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.

holliind. Neocoms, p. 121.

Description —Shell elongate, much compressed, inequilateral, length equal to
more than twice the height. Anterior margin rounded, curving rapidly to join
the slightly curved ventral margin. Posterior margin oblique, forming an angle
with the ventral margin. A shallow furrow passes from the umbo to the middle
of the ventral margin. Umbones small, curved forward. A sharp carina extends
in a curve from the umbo to the postero-ventral angle, and cuts off a narrow,
flattened, postero-dorsal area. Ornamentation consists of fine radial ribs on the
anterior and posterior parts of the valves, especially just in front of the carina ;
growth-lines distinct.

172 CRETACEOUS LAMELLIBRANCHIA.

Measurements :

(1) (2) (3) (4)
Length 39°2 : 39 ; 38 : 36 mm.
Height 7 ; 16 : G25 152}

(1—4) Crackers, Atherfield.

Affinities—The English specimens differ from the figure of T. Carteroni given
by d’Orbigny in the greater curvature of the carma, the narrower postero-dorsal
area, and the greater upward bend of the anterior end of the shell. Professor
Boule has kindly examined the specimen figured by d’Orbigny, and states that
the carina is more curved and the postero-dorsal area narrower than represented
in the figure; also the anterior part has been restored. Professor Boule has also
compared a photograph of a specimen from Atherfield with d’Orbigny’s specimen
and considers that they do not differ specifically. Pictet and Campiche were able
to compare English with French specimens, and the principal difference which they
noted was the occurrence of fine radial ribs on the posterior part of the shell in
English specimens; but I find that those ribs are indistinct or absent in specimens
which are not quite perfectly preserved.

The figure of 7’. angulata given by Deshayes appears to differ from 7’. Carteroni
in its more elongate form and the greater length of the anterior region, but these
differences are probably due to the imperfection of the specimen. Previous writers
have not regarded it as distinct from d’Orbigny’s 7’. Carteroni.

Stoliczka regarded 7’. Carteront as a typical Tellina. It resembles closely the
sub-genus Phylloda, Schumacher.

One specimen from Atherfield (Plate XXVI, fig. 17) differs from the other
examples of this species in the occurrence of strong radial ribs on the posterior
part of the shell. It may be only a variety of 7. Carteront.

Type.—From the Neocomian of Vendeuvre ; the original cannot be found. The
specimen figured by d’Orbigny came from Marolles.

Distribution—Lower Greensand (Crackers) of Atherfield. Atherfield Beds
of Hast Shalford.

TELLINA STRIATULOIDES, Stoliczka, 1870. Plate XXVI, figs. 18, 19; Plate XXVII,
fic: I.

fo)

1824. Tenuina srriatua, J. de C. Sowerby. Min. Conch., vol. v, p. 79, pl. eeeelvi,
fig. 1 (non T. striatula, Olivi,
Bolten, Lamarck).

1850. = — A. dOrbigny. Prodr. de Pal., vol. ii, p. 159.

1854. — ; J. Morris. Cat. Brit. Foss., ed. 2, p. 226.

TELLINA. 173

1865. Truiina striatuLa, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser.
4), p. 139.
1870. “= (TELLINELLA) STRIATULOIDES, F’. Stoliczka. Palseont. Indica, Cret.
Fauna 8. India, vol.
il, p. 123.

Description—Shell elongate-oval, compressed, inequilateral; length equal to
about twice the height ; the anterior part longer than the posterior part. Anterior
margin rounded. Ventral margin slightly curved, making an angle with the
posterior margin. Posterior margin oblique, curved near the postero-ventral
angle, and forming an obtuse angle with the postero-dorsal margin. Umbones
inconspicuous, only slightly curved. A rounded carina extends in a nearly straight
line from the umbo to the postero-ventral angle, and cuts off a flattened postero-
dorsal area. Ornamentation consists of small radial ribs on the postero-dorsal area
and on the part just in front of the carina; also on a small part of the shell near
the anterior margin. Fine concentric lines are also present, and are more
distinct on the anterior and posterior parts of the shell than elsewhere. Pallial
sinus relatively small, somewhat angular.

Measurements :
Q) (2)
Length : 30 ; 27 mm.
Height . 145 . 132 ,,

(1—2) Blackdown.

Affinities.—Stoliczka placed this species in the sub-genus 'ellinella, with which
it agrees closely in external form, but the oblique cardinal teeth resemble more
closely those of the sub-genus Paleomera.

Type.—From Blackdown; in the British Museum.

Distribution.—Upper Greensand (zone of Schlenbachia rostrata) of Blackdown
and Haldon. Recorded by Jukes-Browne from the higher part of the zone of
Pecten asper in North Dorset.

Section—Patmomara, EF’. Stoliczka, 1870.

(‘ Palaont. Indica, Cret. Fauna 8. India,’ vol. iii, p. 116.)
Tectina (PaLZom@ra) inaquatis, Sowerby, 1824. Plate XXVII, figs. 2—8.

1824. Tenia mmevatis, J. de C. Sowerby. Min. Conch., vol. v, p. 80, pl.
cecelvi, fig. 2.
1850. Arcopacia — A.d@’Orbigny. Prodr. de Pal., vol. ii, p. 158 (partim).
1854. TreLiina _ J. Morris. Cat. Brit. Foss., ed. 2, p. 226.
23

174 CRETACEOUS LAMELLIBRANCHIA.

? 1868. Trnurna iInmQuauis, A. Briart and F. L. Cornet. Meule de Bracquegnies
(Man. cour. et Mém. des Sav.
Ctrangers, vol. xxxiv), p. 77, pl.
vill, figs. 24, 25.

1870. Anrcopacia — (Linear), F. Stoliczka. Paleont. Indica, Cret.
Fauna 8. India, vol.

iii, p. 124.
Non 1845. Tenia — ?, H. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 239.

Description.—Shell oval, moderately inequilateral; length rather more than
1} times the height; left valve less convex than the right. Anterior part of
valves rounded. Posterior margin convex, subtruncate, more or less oblique,
forming a blunt angle with the ventral margin. A slight carina extends from the
umbo to the postero-ventral angle and cuts off a flattened postero-dorsal area.
Umbones moderately prominent. Pallial sinus large, rounded. Postero-dorsal
area ornamented with small radial ribs; the remainder of the shell smooth
except for growth-lines.

Measurements :

(1) (2) (3) (4) (5) (6)
Length : 29... 28 2¢ . 26°". a0) 2 Simm:
Height a0 dS75 18 bite Gro Aehroe a) pall ae
Thickness . 9 CD On, GO eens Oxon en ae

(1—6) Blackdown.

Affinities —1'. strigata Goldfuss,! from the Aachen Greensand, is similar in
form to 7’. iuequalis, but possesses fine radial ornamentation over the entire surface
of the shell. 7. Royana, d Orbigny,* is also similar in form, but appears to be more
nearly equilateral and without radial ribs.

A species of T'ellina found in the Meule de Bracquegnies was referred to
T’. inequalis by Briart and Cornet, but it appears to differ in some respects from
the latter. The specimens which I have seen from Bracquegnies are not
sufficiently well preserved to enable me to express a definite opinion as to their
relationship to 7. inequalis.

Type.—From the Upper Greensand of Blackdown ; in the British Museum.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown
and Haldon. Recorded by Jukes-Browne from the Upper Greensand of Devizes
and the Isle of Wight.

1 « Petref. Germ.,’ vol. ii (1840), p. 234, pl. exlvii, fig. 18. Holzapfel, ‘Die Mollusk. Aachen.
Kreide’ (Paleontographica, vol. xxxv, 1889), p. 159, pl. xi, figs. 6-10. This species is the type of the
sub-genus or section Palemera, Stoliczka, 1870.

2 *Pal. Frang. Terr. Crét.,’ vol. iii (1845), p. 422, pl. ecelxxx, figs. 9-11.

TELLINA. |

S|
Or

Sub-genus—Linearia, 7’. A. Conrad, 1860.

(‘ Journ. Acad. Nat. Sci. Philad.,’ ser. 2, vol. iv, p. 279, and ‘ Amer. Journ. Conch.,’ vol. vi
[1870], p. 73.)

Teriina (Linzarta), sp. Plate XXVII, fig. 9.

Deseviption—Shell oval, moderately convex with flattened sides, nearly
equilateral. Anterior margin rounded. Ventral margin slightly convex. Posterior
margin slightly truncated, rounded. Umbones inconspicuous. Postero-dorsal
region slightly compressed, but not limited by a carina.

Ornamentation consists of numerous, strong, regular, concentric ribs separated
by narrow grooves; and a few small radial ribs on the anterior and posterior
parts, those on the latter sometimes not reaching the margin. Length 16°5 mm.;
height 10°5 mm.

Affinities—This species, of which only a few examples have been seen, is
closely allied to, if not identical with, 7’. Rauliniana (VOrbigny),! but the posterior
ribs are less prominent. The shell is less elongate than is d’Orbigny’s type, but
searcely differs in this respect from the example figured by Pictet and Campiche. — It

is more elongate and has the postero-dorsal region less flattened than in
T. subconcentrica (V’Orbigny).? T'. subhercynica, Maas, is another similar form.

Distribution—Lower Greensand (Crackers) of Atherfield. Atherfield Beds of

East Shalford.*

Tenia (Linearta) suprenvistriata, @’ Orbigny, 1850. Plate XXVII, figs. 10O—13.

1836. AmpuipEsMA? TENuIsTRIATUM, J. de C. Sowerby. Trans. Geol. Soc., ser. 2,
vol. iv, pp. 239, 341,
pl. xvi, fig. 7.
1850. Tennina suprenvrsrriata, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 159
(non T. tenuistriata, Deshayes,
1824).
1854. AMPHIDESMA? TENUISTRIATUM, J. Morris. Cat. Brit. Foss., ed. 2, p. 183.

1 For references see p. 176, footnotes 1 and 2.

2 Some specimens from the Folkestone Beds of Folkestone agree in form with 7. subconcentrica,
but owing to the imperfect preservation of the surface the character of the ornamentation cannot be
made out satisfactorily.

8 Tt is possible that Tellina xqualis, Mantell (nom. nud.), from the Lower Greensand of Parham,
may be the form described above. Mantell, ‘ Trans. Geol. Soc.,’ ser. 2, vol. iii (1829), p. 211.

176 CRETACEOUS LAMELLIBRANCHIA.

1865. TELLINA suBTENUISTRIATA, F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal.
Suisse, ser. 4), pp. 132,
138.
1870. AmpHipESMA TENUISTRIATUM, F’. Stoliczka. Paleont. Indica, Cret. Fauna
S. India, vol. ii, p. 111
(? Thracia or Tellina).

Description.—Shell oval, of moderate convexity, nearly equilateral. Anterior
margin rounded ; ventral margin moderately convex ; posterior margin truncated,
more or less oblique, forming a blunt angle with the ventral margin, and an obtuse
angle with the postero-dorsal margin. Umbones rather broad, scarcely curved.
Postero-dorsal part of shell compressed and flattened.

Ornamentation consists of numerous strong, regular, concentric ribs, and of a
few small radial ribs on the anterior part, and of a larger number on the postero-
dorsal region and the part just in front of it.

Measurements :

eb) (2) (3) (4)
Length : 19 ; 18 : ile : 13 mm.
Height : 1375 ee. 13 : i ro Tae Dis:

(1—4) Blackdown.

Ajjinities.—This species resembles Tellina Rauliniana (dV Orbigny),' but possesses
a relatively shorter and higher shell, with a more convex ventral margin and more
numerous radial ribs. In form it approaches more nearly the examples from the
Gault of the Perte du Rhone figured by Pictet and Campiche,” but in the latter
the posterior extremity is more angular and the posterior ribs more prominent and
limited to the postero-dorsal region.

T'. subtenuistriata also resembles 7’. subconcentrica (d’Orbigny),’ but is more
nearly equilateral and the ventral border is more convex.

It differs from the species from the Lower Greensand described above in the
flattened postero-dorsal region, the more angular posterior extremity, the smaller
apical angle, the larger curvature of the ventral margin, and greater relative
height. 7. subhercynica, Maas,‘ is another similar form.

Remarks.—The type is somewhat imperfectly preserved, but the radial ribs on
the anterior and posterior parts, which are not shown in Sowerby’s figure, can be
made out satisfactorily. The size of the apical angle and the outline of the shell
vary in different examples.

1 «Pal. Frane. Terr. Crét.,’ vol. iii (1845), p. 411, pl. ecelxxviii, figs. 7-10.

> Pictet and Campiche, ‘Terr. Crét. Ste. Croix’ (1865), p. 141, pl. cix, figs. 1-3.

8’ Op. cit., p. 410, pl. ecclxxviii, figs. 1-6, and ‘Prodr. de Pal.,’ vol. iti (1850), p. 75. Pietet and
Renevier, ‘ Foss. Terr. Aptien’ (Matér. Pal. Suisse, ser. 1, 1856), p. 69, pl. vii, fig. 7.

' «Zeitschr. der deutsch. geol. Gesellsch.,’ vol. xlvii (1895), p. 258, pl. vi, figs. 3, 4.

MACTRA. 177

Type.—From Blackdown; in the Bristol Museum.
Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown.

TELLINA (LingariA) sp. Plate XXVII, figs. 14—16.

Description.—Shell oval, moderately convex, with flattened sides, nearly equi-
lateral. Anterior and posterior margins rounded. Ventral margin only slightly
curved, and nearly parallel with the dorsal margin. Umbones broad, nearly median.
Postero-dorsal part of valve flattened, rather large, limited by a faint carina.

Ornamentation consists of numerous small, regular, concentric ribs, and
numerous small radial ribs on the postero-dorsal area and near the anterior end.

Measurements :
(1) (2) (3)
Length iby : 15 14. mm.
Height ; 12 10 : eee

(1—3) Blackdown.

Affinities—This species resembles 7’. auliniana (d’Orbigny), but the radial
ribs are much more numerous. It is also similar to the form from the Lower
Greensand described above, and to 7’. subhercynica, Maas.

Distribution. Upper Greensand (zone of Schlanbachia rostrata) of Blackdown.

Family—MACTRIDA, Gray.

Genus—Macrra, Linneus, 1767.
(‘ Syst. Nat.,’ ed. 12, vol. i, p. 1125.)

Mactra, sp. Plate XXVII, figs. 17, i8.

A few specimens which resemble Mactra externally, but of which the hinge has
not been seen, were found in the Lower Greensand (Ferruginous Sands) of Shank-
lin by the late C. J. A. Meyer. They are rather larger and relatively higher than
M. angulata, and the carina is less distinct. The surface of the shell is ornamented
with small concentric ribs.

Macrra ancutata, Sowerby, 1836. Plate XXVII, figs. 19—23.

1836. Macrra ? ANGULATA, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp. 241, 341, pl. xvi, fig. 9

1850. Macrra aneunata, A. d'Orbigny. Prodr. de Pal., vol. ii, p. 158.

_
ba |
we

CRETACEOUS LAMELLIBRANCHIA.

1854. Macrra aneurata, J. Morris. Cat. Brit. Foss., ed. 2, p. 209.

1865. = = F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Mater. Pal.
Suisse, ser. 4), p. 129.

1870. = — F’. Stoliczka. TPaleont. Indica, Cret. Fauna S. India,

vol. iii, pp. 55, 56.

Non 1851. — — J. Miiller. Petref. der Aachen. Kreidef., pt. 2, p. 66
(= M. Bosquetiana, Stoliezka).
— 1901. — — F. Sturm. Jahrb. d. k. preuss. geol. Landesanst. fiir.

1900, vol. xxi, p. 84, pl. viii, fig. 1.

Description.—Shell small, convex, subtriangular, slightly imequilateral, with
the antero- and postero-dorsal parts bending rapidly to the margins. Antero-
dorsal margin lone. Anterior margin rounded. Ventral margin convex, forming
an angle with the posterior margin, which is truncated, oblique, and slightly convex.
Umbones prominent, pointed, curved inwards, with a carina which extends in a
gentle curve to the postero-ventral angle. Ornamentation consists of fine con-
centric ribs, which become fewer and stronger near the antero-dorsal and postero-
dorsal margin.

Measurements :

(1) (2) (3) (4)
Length 14 : 113} : 10 5 8 mm.
Height 12 Osa ee 8 : (eae

(1—4) Blackdown.

Affinities—In form and ornamentation M. angulata resembles M. Warrenana,
Meek and Hayden,' but the latter is of larger size and the umbones show a distinet
anterior curvature.

A species found in the Aachen Greensand, now known as M. Posquetiana,
Stoliczka, was identified with M. angulata by Miiller, but is distinguished from
the latter, as Stoliezka pointed out, by its greater length, smaller convexity, rounded
posterior margin, and other characters.

Type.—From Blackdown ; in the Bristol Museum.

Distribution—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown
and Haldon. Recorded by Barrois from the Upper Greensand of Lulworth and
by Jukes-Browne from the equivalent of the Blackdown Beds at Sidmouth.

1 Meek, ‘Invert. Cret. and Tert. Foss. U. Missouri’ (1876), p. 208, pl. xxx, fig. 7. Whiteaves,
‘Mesozoic Foss.’ (Geol. Surv. Canada), vol. i (1879), p. 142, pl. xvii, fig. 9, pl. xix, fig. 3.

PTYCHOMYA. ES)

Hamily—V ENERIDAG, Leach.

Genus—Prycuomya, L. Agassiz, 1842.

(‘ Etudes crit. Moll. Foss.’ ; Myes, p. xviii, pl. xi, figs. 3, 4.)

Prycnomys Ropinanpina (W?Orbigny), 1844. Plate XXVII, figs. 24—26.

1842-45. Prycnomya puana, DL. Agassiz. Wtudes crit. Moll. Foss. ; Myes, p. xvill
(1845), pl. xi, figs. 3, 4 (1842).

1844. CRraAssATELLA ROBINALDINA, A. d’Orbiquy. Pal. Franc. Terr. Crcét., vol. iii,

p. 75, pl. celxiv, figs. L1O—13.

1845. — — Ef. Forbes. Quart. Journ. Geol. Soc., vol. i,
p. 241.

1850. _ _- @’ Orbigny. Prodr. de Pal., vol. ii, p. 77.

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 196.

1855. — — G. Cotteau. Moll. Foss. de ’Yonne, p. 71.

1866. Prycuomya — EF. J. Pictet and G. Campiche. Foss. Terr. Crét.

Ste. Croix (Matér. Pal. Suisse,
ser. 4), p. 352, pl. exxvii,
figs. 2—6.
1869. RaproconcHa = T. A. Conrad. Amer. Journ. Conch., vol. v,
p. 47.

Description —Shell oval-oblong, elongate, convex, but with flattened sides, very
inequilateral, anterior part rather higher than the posterior part. Anterior
margin regularly rounded. Ventral margin only shghtly curved, nearly parallel
to the dorsal margin. Posterior margin oblique, ferming an acute angle with the
ventral margin and an obtuse angle with the slightly curved postero-dorsal margin.
Umbones inconspicuous. On the postero-dorsal side of a line from the umbone to
the posterior extremity the shell is flattened. Lunule narrow, elongate.

Ornamentation consists of strong radial ribs, which are sometimes more or less
nodose. Those on the posterior part of the shell are stronger and separated by
broader furrows than those on the anterior part. The ribs which reach the
posterior margin start from the umbo; the others start from a line between the
umbo and a point on the opposite margin which is about a quarter of the distance
from the anterior to the posterior end. In front of this line the ribs form a
considerable curve; behind it they are only slightly curved; the ribs meet at an
acute angle at the line mentioned forming either a A throughout or a chevron M,
on the ventral part. The postero-dorsal margin is ornamented with strong nodose

ridges.

180 CRETACEOUS LAMELLIBRANCHIA.

Measurements :

(1) (2) (3)
Length E 80 ; 70 ‘ 69 mm.
Height : 4A, 39 2 36

(1—3), Perna-bed, Atherfield.

Affinities. Forbes states that English examples of this species were identified
by comparison with French specimens. I have not seen any foreign examples of
P. Robinaldina, but the English specimens appear to differ from those figured by
@Orbigny and by Pictet and Campiche in their greater convexity and larger size,
in the more acute angle which the ribs make at the dorso-ventral line, and in the
somewhat less anterior position of that line. In all these respects the English
examples approach more nearly to P. neocomiensis (de Loriol),' but differ from that
species in their more elongate form. It seems, however, not unhkely that a large
number of specimens might show that P. Robinaldina and LP. neocomiensis are not
specifically distinct. In connection with this, attention may be called to Nucula
(Acila) bivirgata, Sowerby, in which the ornamentation is somewhat similar and
shows considerable variation.

The genus Ptychomya was placed in the Crassatellitidee by Pictet and Campiche
and by Stoliczka. Its resemblance to Circe (Crista) was pointed out and fully
discussed by Dames,” whose view of its systematic position is accepted by Fischer.

Remarks.—The date of the plate on which Agassiz figured Ptychomya plana is
earlier, but the text relating to it is later than d’Orbigny’s figure and description
of Crassatella Robinaldina. Since the specimen figured by Agassiz is rather
unsatisfactory and d’Orbigny’s name has been used by nearly all writers it seems
desirable to retain the latter.

Distribution —Lower Greensand (Perna-bed) of Atherfield. Ferruginous
Sands of Shanklin. Hythe Beds of Hythe, Lympne, and Maidstone.

1 Pictet and Campiche, “ Terr. Crét. Ste. Croix” (‘ Matér. Pal. Suisse,’ ser. 4, 1866), p. 355,
pl. exxvii, figs. 9—12.
2 « Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. xxv (1873), p. 374, pl. xii, figs. 1—4.

Palzontograpbical Society, 1908.

A MONOGRAPH

OF THE

CRETACKOUS LAMELLIBRANCHIA

ENGLAND.

BY

HENRY WOODS, M.A.

UNIVERSITY LECTURER IN PALHOZOOLO

VOL; ii PART Y.

VENERIDA, CARDIDA, DICERATIDH, MONOPLEURID.”,

CORBULIDA.

Paces 181—216; Prares XXVIII—XXXIV.

LONDON:

AND

PRINTED FOR THE PALZONTOGRAPHICAL SOCIETY

1908.

DOSINIOPSIS. 181]

Genus—Dosintopsis, 7. A. Conrad, 1864.

(‘ Proce. Acad. Nat. Sci. Philadelphia,’ p. 213.)

Dosiniopsis susrorunpDA (Sowerby), 1836. Plate XXVIII, figs. 1—6.

1836. CyrHerma suBrorunpbA, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,

pp. 240, 341, pl. xvii, fig. 2.

1850. Venus — A. dOrbigny. Prodr. de Pal., vol. ii, p. 159.
1854. CyTHREREA — J. Morris. Cat. Brit. Foss., ed. 2, p. 201.
1870. Venus — F’. Stoliczka. Paleont. Indica, Cret. Fauna 8.

India, vol. iii, p. 161 (Caryatis).

Description —Shell rather thick, rounded, oval or somewhat orbicular, of small
or moderate convexity ; length rather greater than height; moderately, sometimes
considerably, inequilateral. | Antero-dorsal margin long, concave. Anterior
margin rounded, passing gradually into the considerably curved ventral margin.
Postero-dorsal margin very long, convex, with a considerable ventral slope.
Posterior margin rounded. Umbones small, pointed, close together, slightly
curved anteriorly. Lunule elongate, depressed, distinctly limited. Escutcheon
narrow, depressed, with a sharp border. Pallial sinus rather large, sub-angular.
Ornamentation consists of fine concentric strizw, and growth-lines.

Hinge: In the right valve three strong, nearly straight, diverging cardinal
teeth, of which the anterior and median are closer together and diverge at a
smaller angle than the median and posterior, the last being divided by a shallow
longitudinal groove; there is a small posterior lateral tooth and an elongate
anterior pit. In the left valve the anterior of the three diverging cardinal teeth is
nearly vertical, the median is the stoutest, and the posterior is oblique and slender ;
the anterior lateral tooth is elongate and parallel to the lunular margin; the
posterior lateral is very small.

Measurements :

(1) (2) (3) (4) (5)
Length . 34. ; 31 é 29 : 28 : 26° min.
Height . 32 : 28 265 =. 26 : 23°55,

(1—5) Blackdown.
T'ype.—From Blackdown; in the Bristol Musewm.
Distribution.—Upper Greensand (zone of Nehleenbachia rostrata) of Blackdown.

24

182 CRETACEOUS LAMELLIBRANCHIA.

gs. /—10.

Dosintopsts CAPERATA (Sowerby), 1826. Plate XXVIII, fi

1826. Venus caperara, J. de C. Sowerby. Min. Conch., vol. vi, p. 31, pl. dxviii,
figs. 1-3.

1850. — ~ A. d@Orbigny. Prodr. de Pal, vol. 11, p. 159.

1854. CyruernEa — J. Morris. Cat. Brit. Foss., ed. 2, p. 200.

1865. Venus caperara, I. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p. 189.

1868. -- A. Briart and F. L. Cornet. Meule de Bracquegnies
(Mém. cour. et Mém. des Sav.
étrangers, vol. xxxiv), p. 74, pl
vu, figs. 6—8.

1870. = = I’. Stoliczka. Paleeont. Indica, Cret. Fauna S. India,

vol. i, p. 160 (Caryatis).

? Non 1845. — — A. @Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 445,
pl. ecelxxxv, figs. 9, 10 (V. wniformis,

Prodr. de Pal., vol. ii, p. 236).

Descriplion.—Shell oval, convex, moderately or considerably inequilateral ;
length rather greater than height. Antero-dorsal margin concave. Anterior
margin rounded, passing gradually mto the convex ventral margin. Posterior less
convex than the anterior margin, sometimes subtruncate. | Postero-dorsal margin
long, shghtly convex. Umbones prominent, curved anteriorly. Lunule ovate.
Pallial sinus rather large, sub-angular. Ornamentation consists of strong, regular,
concentric ribs.

Hinge: In the right valve three stout cardinals separated dorsally, the anterior
and median being close together and nearly vertical, the posterior oblique and
divided by a longitudinal groove; there is an anterior elongate pit and a strong
posterior lateral tooth. In the left valve the median is the stoutest of the three
cardinals and is sometimes joined dorsally to the nearly vertical anterior cardinal;
the posterior cardinal is slender and very oblique; the anterior lateral is strong,
elongate and parallel to the lunular margin.

Measurements :

(1) (2
Length . 34 . 3
Height . 305. 2

) (3) (4) (5) (6) (7) 8)
L800 (28) 5 a2 Oe 2D ee oem
9 .. 26 PF -24ebr 22) 2S eee a Ge eles
(1—8) Blackdown.
Remarks.—Internal casts from the Folkestone Beds of Pulborough were
referred to this species by Forbes. I have not seen any specimens which would

enable me to record the occurrence of /). caperata im the Lower Greensand.

CYPRIMERIA. 183

T'ype.-—From Blackdown; in the British Museum.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown
and Haldon. Recorded by Barrois from the Upper Greensand of Lulworth, and
by Jukes-Browne from the Upper Greensand of the Isle of Wight.

Genus—Cyprimerta, 7’. A. Conrad, 1864.

(‘ Proce. Acad. Nat. Sei. Philad.,’ 1864, p. 212, and ‘Amer. Journ. Conch.,’ vol. ii, 1866, p. 102.
Stoliezka, ‘ Palzeont. Indica, Cret. Fauna 8. India,’ 1870, p. 157.)!

Sul-genus—Cycrorisma, W. H. Dall, 1903.

(‘ Proc. U.S. Nat. Mus.,’ vol. xxvi, 1903, p. 357. Syn. Cyclothyris, T. A. Conrad in W. CG. Kerr’s
‘Geol. Rep. N. Carolina,’ vol. i, Appendix 1 (1875), p. 8. Non Cyclothyris, M’Coy, 1844.)

Cyprimenta (Cycrorisma) vecrensis (Forbes), 1845. Plate XXVIII, figs. 11—18.

1845. Venus vecrensis, 2. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 240, pl. ii,

fio. 4.
1850. — — A. d’Orbiqny. Prodr. de Pal., vol. ii, p. 118.
1854. = — J. Morris. Cat. Brit. Foss., ed. 2, p. 231.
1865. — — FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p. 188.
1870. — F. Stoliczka. Palwont. Indica, Cret. Fauna S. India,
vol. iii, p. 160.
? 1883. — - W. Keeping. Foss., ete. Neoc. Upware and Brickhill,
p. 125.

Description.—Shell oval, or nearly orbicular, a little longer than high, regularly
convex, slightly or moderately inequilateral. Margin rounded, Umbones small,
pointed, somewhat curved forwards. Lunule indistinct, not impressed, limited by a
faint line. Pallial sinus angular, directed upwards. Margins of valves smooth.
Surface of shell smooth except for small, inconspicuous, concentric ridges, and
occasional growth-rings.

Hinge: In the right valve an anterior and a median cardinal and two posterior
laminar teeth (which together represent the posterior cardinal) diverge from
under the umbo; the anterior is directed forwards, the median is nearly vertical,

1 The following European species are referred by Conrad and by Stoliczka to the genus
Cyprimeria: Cyclina primeva, Zitt., Dosinia cretacea, Zitt., Circe discus (Math.), Circe conce ntrica,
Zitt., and Arcopagia rotundata, VOrb. Holzapfel figures Cyprimeria Geinitzi (Miill.) and C. moneta,
Holz., from the Aachen Greensand.

184. CRETACEOUS LAMELLIBRANCHIA.

and the two posterior slope obliquely backwards. In the left valve a long, oblique
laminar, posterior cardinal; a median cardinal (which is divided); and an
anterior cardinal, diverge under the umbo, from which they are separated by a
narrow space or channel. In front of the anterior cardinal the anterior part of
the hinge-plate is concave.

Measurements :

(1) (2) (3) (4) (5)
Length . 38 : 32 : 31 2 28 : 24 mm.
Height. 34 2 Bi 29 26 , PIPPI Ws

(1—5) Crackers, Atherfield.

Affinities.—This species shows some resemblance to Venus vendoperana
(Leymerie), especially to the example figured by Pictet and Renevier,' but the
umbones are less prominent and the lunule is less distinct.

T'ype.—The type came from the Crackers of Atherfield, but cannot now be
found.

Distribution.—Lower Greensand (Crackers) of Atherfield. Recorded from
the Atherfield Clay and Bed vii of Atherfield by Fitton. Recorded by Topley
from the Atherfield Beds of Peasmarsh and Shalford.?

Cyprimenia (Cyciorisma) parva (Sowerby), 1826. Plate XXVIII, figs. 19—23;
Plate XXIX, figs. 1—3.

1826. Venus parva, J. de C. Sowerby. Min. Conch., vol. vi, p. 32, pl. dxviii,
figs. 4—6.
1845. Lucia ¥ sonrpuna, B. Forbes. Quart. Journ. Geol. Soc., vol. i, }. 239, pl. 1,
fig. 7.
1850. Venus parva, 4. d’Orbigny. Prodr, de Pal., vol. ii, p. 159 (not Blackdown).
- Lucina sonrpuna, d’Orbigny. Tbid., vol. ii, p. 118.
1854. Cyrnerna parva, J. Morris. Cat. Brit. Foss., e!. 2, p. 201 (partim).
—- Luctna sonipuna, Morris Tbid., ed. 2, p. 208.
1865. Venus parva, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matér. Pa]. Suisse, ser. 4), p. 188.
1870. -- — F.Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. iti,
p. 160 (Caryatis).
— Lucina ? sonmpuna (? Mysra), Stoliczka. Ibid., vol. iii, pp. 252, 262.
21895. Venus c/. parva, E. Tiessen. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlvii,
p- 484.

1 Pictet and Renevier, ‘Foss. Terr. Aptien’ (‘ Matér. Pal. Suisse,’ ser. 1, 1855-56), p. 71, pl. vii,
fig 9. Pictet and Campiche, ‘Terr. Crét. Ste. Croix’ (‘Matér. Pal. Suisse,’ ser. 4, 1865), p. 181, pl. exi,
fig. 12.

2 T have not seen the specimen recorded by Keeping from Upware.

CYPRIMERIA. 185

Non 1840. Venus parva, A. Goldfuss. Petref. Germ., vol. ii, p. 246, pl. cli, fig. 4
(V. Goldfussi, Geinitz, 1850; V. subparva,
d’Orbigny, 1850).

— 1841. ae — FF. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p. 72 (Venus subinflera, Romer, 1836).
— 1846. = — A. EH. Reuss. Die Verstein. der béhm. Kreideformat., pt. 2,
p. 20, pl. xli, figs. 16, 17.
== 1863: a — A. v. Strombeck. Zeitschr. der deutsch. geol. Gesellsch.,
vol. xv, p. 146.
— 1868. — — A. Briart and F. L. Cornet. Meule de Bracquegnies (Mém.

cour. et Mém. des Sav. ¢trangers,
vol. xxxiv), p. 75, pl. viii, figs. 1, 2
— 1877. CytHEreEa parva, G. Bohm. Zeitschr. der deutsch. geol. Gesellsch., vol. xxix,
p. 241.
— 1883. Venus cf. parva, A. Fritsch. Stud.im Gebiete der bohm. Kreideformat., iii,
Iserschicht., p. 109, fig. 77.
— 1885. Venus parva, F. Nitling. Die Fauna d. baltisch. Cenoman. (Paleont.
Abhandl., vol. ii), p. 32, pl. v, fig. 11.
—=— 1893: — — Fritsch. Op. cit., v, Priesen. Schicht., p. 98, fig. 118.

Description.—Shell small, oval, convex, moderately inequilateral. | Antero-
dorsal margin slightly concave, or nearly straight, forming a rounded angle with
the anterior margin which curves rapidly to join the convex ventral margin.
Posterior margin rounded or subtruncate. Postero-dorsal margin slightly convex.
Umbones rather prominent, curved inwards and forwards. Lunule broad, ovate,
more or less projecting, limited by a groove. Pallial sinus large, angular.
Ornamentation consists of small, somewhat irregular, concentric ribs, and occasional
growth-rings.

Hinge: In the right valve the anterior and median cardinals are stout and
nearly parallel, and the two posterior teeth (which represent the posterior cardinal)
are oblique and diverging; in front of the anterior cardinal is a groove, bounded
by a ridge above and below, parallel to the inner margin of the hinge-plate. In
the left valve the anterior and median cardinal teeth diverge widely under the
umbo and the posterior cardinal is oblique; the anterior cardinal is continued
forward into a ridge along the inner margin of the hinge-plate.

Measurements :

(1) (2) (3) (4) (5) (6) (7) (8)
Seam. 2st. 20). 2006. U9 ll. dG. Cd. 10 mm.
Pee ize, 175.-17 - 16 . 14, 12 . 85,

(1) Perna-bed, East Shalford.
(2—8) Crackers, Atherfield.
Afjinities—The differences between this species and (’. (( 'yclorisma) rotomagensis
are given below.
The form from Bracquegnies, which was referred to Venus parva by Briart and
Cornet, is less elongate.

186 CRETACEOUS LAMELLIBRANCHIA.

The hinge differs from that of other species of Cyclorisma in that the anterior
tooth in the left valve is continued forwards into a ridge at the inner margin of
the hinge-plate.

Lucina ? solidula, Forbes, appears to be identical with Venus parva, Sowerby ;
the type is missing, but other specimens which are in the Museum of the Geological
Society and were probably identified by Forbes, are undoubtedly examples of
V. parva. The type of Lucina ? solidula, so far as one can judge from the figure,
seems to have been rather shorter than most examples of Venus parva.

Venus Orbignyana, Forbes,’ from the Crackers of Atherfield, is stated to be
allied to V. parva. The type is missing, but a specimen named J’. Orbignyana in
the Museum of the Geological Society appears to be a small example of Cyprina
Saussurt (p. 131).

Remarks.—Kxamples of this species vary somewhat in convexity, in relative
height and length, im the prominence and position of the umbones, and in the
projection of the lunule at the margin where the valves meet. The types are
internal casts from Parham, and they agree, except in being slightly more convex,
with casts from Hast Shalford, where specimens with the shell preserved are also
found. The latter do not differ from the perfectly preserved specimens found in
the Crackers of Atherfield.

T'ype.—From the Sandgate Beds of Parham Park, in the British Museum.

Distribution.—Lower Greensand: /’erna-bed, Crackers, and Bed 45 of Ather-
field. Perna-bed of Sandown. <Atherfield Beds of Peasmarsh and Shalford.

Sandgate Beds of Parham Park.

Cyprmerta (Cycnortsma) roroMaGcEnsis (d’Orbigny), 1845. Plate XXIX, figs. 4—6.

1845. Venus rnoromacensts, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. i, p.
443, pl. ecelxxxv, figs. 1—5.

1850. ROTHOMAGENSIS, @’Orbigny. Prodr. de Pal., vol. ii, p. 194.

1865, roromaGensis, I’. J. Pictet and G@. Campiche. Foss. Terr. Cret.
Ste. Croix (Matér. Pal. Suisse,
ser. 4), p. 190.

1870. F. Stolickza. Paleont. Indica, Cret. Fauna 8.
India, vol. iii, p. 161 (? Caryatis).

Remarks.—The English examples of this species are internal casts occasionally
with small portions of the shell preserved. D’Orbigny’s specimens were obtained
1 «Quart. Journ. Geol. Soc.,’ vol. i (1845), p. 240, pl. ii, fig. 5; d’Orbigny, ‘Prodr. de Pal.,’
vol. ii (1850), p. 118; Morris, ‘Cat. Brit. Foss.,’ ed. 2 (1854), p. 231; Pictet and Campiche, ‘ Foss.
Terr. Crét. Ste. Croix’ (‘Muatér, Pal. Suisse,’ ser. 4, 1865). pp. 184, 188; Stoliezka, ‘Paleont. Indica,

Cret. Fauna 8. India,’ vol. iii (1870), p. 160.

CYPRIMERIA. 187

from the Cenomanian of Rouen. Hnelish specimens agree with those found at
Rouen, except that in many cases the shell is somewhat shorter relatively. The
surface is ornamented with concentric ribs. In C. (Cyclovisina) rotomagensis the
shell is more convex, more inequilateral, and the postero-dorsal margin has a
greater slope than in C. (Cyclorisima) parva. Che hinge appears to be unknown.

Distribution.—Base of the Chalk Marl of Maiden Newton and Chard. Chloritic
Marl of Melbury, Woolcombe, Maiden Bradley and the Isle of Wight.’

Cyprimerta (Cyctorisma) rapa (Sowerby), 1827. Plate XXIX, figs. 7—13.

1827. Venus rasa, J. de C. Sowerby. Min. Conch., vol. vi, p. 129, pl. dlxvii, fig. 3.

1850. — — A.W Orbigny. Prodr. de Pal., vol. u, p- 159 ( partim).
1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 230 (partim).
1868. o — A. Briart and F. L. Cornet. Meule de Bracquegnies (Mém.

cour. et Mém. des Sav. ¢trangers,

vol. xxxiv), p. 73, pl. viii, figs.

9, 10. :
1870. = — FHF. Stoliczka. Palaont. Indica, Cret. Fauna §. India, vol. iii,
p. 160,
1875. — — H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto-

graphica, vol. xx, pt. 2), p. 65, pl. XViil,
figs. 9, 10.
? 1882. — J. Kiesow. Schrift. d. nat. Gesellsch. in Danzig, N.F., vol. v,

p- 239.

? 1585. — F. Notling. Die Fauna d. baltisch. Cenoman. (Palwont.
AbhandL., vol. ii), p. 32, pl. vi, fig. 1.
Non 1840. — — A. Goldfuss. Petref. Germ., vol. ii, p. 247, pl. cli, fig. 6 (V.
subjaba, VOrbigny ).
—— iheyish — — H.B. Geinitz. Die Verstein. von Kieslingswalda, p. 13, pl. 11,
figs. 7—9.
y— 1845. — — A.dOrbigny. Pal. Frang. ‘Terr. Crét., vol. iil, p. 444, pl.
ceelxxxv, figs. 6—8.
— 1846 — A. EB. Reuss. Die Verstein. der bohm. Kreideformat., pt. 2,
p. 21, pl. xli, fig. 12.
— 1847. — J. Miiller. Petref. der Aachen. Kreidef., pt. 1, p. 24.
— 1859. — unmersa, Miller. Ibid., Supplement, p. 13.
-— 1863. — pana, A. v. Strombeck. Zeitschr. d. deutsch. geol. Gesellsch., vol.

xv, p. 147.

1 An inpperfect left valve from the Cenomanian (Bed 12) of Whitecliff, South Devon, was
identified by C. J. A. Meyer with Venus Goldfussi, Geinitz, * Das Quadersandst. oder Kreidegeb. in
Deutschland’ (1850), p. 154, pl. x, figs. 7, 8; ‘ Das Elbthalgeb. in Sachsen’ (‘ Paleontographica,’ vol.
xx, pt. 2, 1873), p. 67, pl. xviii, figs. 16, 17. There is not sufficient evidence to coufirm this identifica-
tion ; the anterior part of the specimen is more produced than in the case of the examples figured by
Geinitz.

188 CRETACEOUS LAMELLIBRANCHIA.

Non 1863. Venus rasa, Rk. Drescher. Ibid., vol. xv, p. 343.

1884. Cyprimexta rasa, L. Holzapfel. Ubid., vol. xxxvi, p. 467, pl. vii, fig. 1.
1889. ares rasa, H. Holzapfel. Die Mollusk. Aachen. Kreide (Paleonto-
graphica, vol. xxxv), p. 165, pl. xii, figs. 7-10.
— 1897. Venus (Tapes) rapa, A. Mritsch. Stud. im Gebiete der bohm. Kreide-
format., vi, Chlomek. Schicht , p. 63,

fig. 80.
1901. F. Sturm. Jahrb, d. k. preussisch. geol. Landesanst.
fiir 1900, vol. xxi, p. 82.

Description.—Shell oval, of moderate convexity, with flattened sides, con-
siderably inequilateral. Antero-dorsal margin short, slightly concave. Anterior
margin rounded, passing gradually into the slightly convex ventral margin.
Postero-dorsal margiu long, slightly convex, with a moderate or considerable
ventral slope. Porterior margin short, rounded or subtruncate. Umbones small.
Lunule elongate, not impressed, faintly limited. Ornamentation consists of small,
regular, concentric ribs.

Hinge: In the right valve the anterior and median cardinals are stout, diverge
shghtly, and are directed forwards, and reach the lower margin of the hinge-
plate; the two posterior teeth (which represent the posterior cardinal) are
laminar, oblique and diverging. In the left valve the anterior and median
cardinals are rather stout and diverge; the posterior cardinal is slender and
oblique. In front of the anterior cardinal there is a concave space on the hinge-
plate im both valves.

Measurements :

(1) (2) (3) (4) (5)
Leneth . 30 ; 29 : 29 : 28 27 mm.
Height. 25 : 24. 22 ; 21 yep
(1—5) Blackdown.

Affinities—Venus Archiaciana, @Orbigny,! from the Senonian of Charente-
Inférieure, is somewhat similar in form to C. (Cyclorisma) fuba, but the surface
of the shell is smooth.

A species found in the Aachen Greensand has been identified by Goldfuss,
Holzapfel, and others with Sowerby’s Venus faba, but was regarded as distinet by
@Orbigny and G. Miiller. It differs from Sowerby’s species in the greater
curvature of the ventral margin and the more pointed posterior extremity ; also the
posterior teeth in the right valve are less widely separated and are more oblique.

In @Orbigny’s figure of Venus faba the ornamentation is coarser than in English
examples, but a specimen from the Cenomanian of Rouen (one of the localities
cited by d’Orbigny) differs but little in this respect from Blackdown specimens.

Remarks.—Vhe principal variation consists in the amount of the ventral slope

'<Pal. Frang. Terr. Crét.,’ vol. iii (1845), p. 449, pl. ceclxxxvi, figs. 6, 7.

CLEMENTIA. 189

of the postero-dorsal margin. In the type specimen that slope is small, so that
the outline of the shell is distinctly oval. The position of the umbones also varies,
so that some specimens are more inequilateral than others.

Specimens found in the Gault of Black Ven are usually somewhat crushed and
often larger than Blackdown examples; some are more elongate and agree closely
with Venus sublevis, Sowerby (see below).

Type.—From Blackdown; in the British Museum.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown
and (?) Devizes. Gault of Black Ven.

Cyprimerta (Cyctorisma) susLavis (Sowerby), 1836. Plate XXIX, fig. 14.
1836. Venus? susnavis, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp.

242, 342, pl. xvii, fig. 5.

1850. Venus susiavis, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 159.

1854. — a J. Morris. Cat. Brit. Foss., ed. 2, p. 231.
1870. — — F. Stoliczka. Paleont. Indica, Cret. Fauna 8S. India,

vol. iii, p. 161.

Remarks.—The only specimen which I have seen is the type. It differs from
CO. (Cyclorisma) faba only in being more elongate, and seems to be merely an
individual variation. Venus immersa, Sowerby,! also known by the type only
(Plate XXIX, fig. 15), does not appear to differ from V. sublevis. The types of
both are in the Bristol Museum and come from the Upper Greensand of Blackdown.

Genus—CiEMeEntia, J. H. Gray, 1840.
(‘Synopsis Brit. Mus.,’ p. 149.)

Sub-genus—Fraventia, A. J. Jukes-Browne, 1908.
(‘ Proc. Malacol. Soc.,’ vol. viii, p. 167.)

Crementia (FiaventiA) Ricorpeana (d’Orbigny), 1845. Plate XXIX, figs. 16—18.

1845. Venus Ricorpeana, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 431,
pl. ceelxxxii, figs. 1, 2.

1 Sowerby, ‘Trans. Geol. Soc.,’ ser. 2, vol. iv (1836), pp. 242, 342, pl. xvii, fig. 6; d’Orbigny,
‘Prodr. de Pal.,’ vol. ii (1850), p. 159; Morris, ‘Cat. Brit. Foss.,’ ed. 2 (1854), p. 231; Stoliezka,
‘ Palewont. Indica, Cret. Fauna S. India,’ vol. iii (1870), p. 161. Non Venus immersa, Miiller, * Petref.
der Aachen. Kreidef.,’ Supplement (1859), p. 13; Reuss, ‘ Die Verstein. der béhm. Kreideformat.,’
pt. 2 (1846), p. 20, pl. xli, fig. 11; Kner, ‘ Denkschr. d. k. Akad. Wissensch. Wien, Math.-Nat. Cl.,’
vol. iii (1852), p. 311, pl. xvi, fig. 20.

25

190 CRETACEOUS LAMELLIBRANCHIA.

1850. Venus Ricorpeana, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 76.

1855. —— = G. Cotteau. Moll. Foss. de l’Yonne, p. 64.

1865. — — FP. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p. 169.

1870. — — F. Stoliczka. Palwout. Indica, Cret. Fauna 8. India,

vol. ili, p. 159.

Description.—Shell oval, convex with flattened sides, considerably inequilateral,
anterior part higher than the posterior part. Anterior margin regularly rounded,
passing gradually into the slightly curved ventral margin. Postero-dorsal margin
long, convex, with a considerable ventral slope. Posterior margin short, oblique,
forming a rounded angle with the ventral margin. Umbones_ broad, curved
forwards. The part of the shell behind a line between the umbones and the
postero-ventral angle slopes rapidly from the flattened sides. Lunule elongate,
limited by a groove. Escutcheon elongate, deep, limited by a sharp edge.

Ornamentation consists of sharp concentric ridges. Pallial sinus angular,
somewhat ascending.

Measurements :

(1) (2) (3) (4) (5)
Length ; 56 ; 52 é 52 : 50 . 43 mm.
Height ‘ A? . 40 5 39 . 35 é Bae:
(1) Atherfield Beds, Peasmarsh.
; (2, 5) Perna-bed, Atherfield.

(3) Hythe Beds, Lympne.
(4) Hythe Beds, Pulborough.

Affinities.—English specimens differ from d’Orbigny’s figure in the more rapid
ventral slope of the postero-dorsal margin. J am indebted to Professor Boule for
comparing photographs of specimens from the Lower Greensand with the examples
in the d’Orbigny collection which appear to be the types, and he states that in
the latter the shell is less elongate and the postero-dorsal border has a greater
slope than in d’Orbigny’s figure, consequently the photographs agree much more
closely with the types than with the figure. M. A. de Grossouvre has been good
enough to lend me a specimen of C. (Hlaventia) Ricordeana from the Lower Aptian
of Seignelay, Yonne, one of the localities mentioned by d’Orbigny, and a
comparison of that with English examples leaves no doubt as to their specific
identity.

The generic position of Clementia (Flaventia) Ricordeana is at present some-
what uncertain since none of the specimens shows the hinge; but on account of
the resemblance in the form of the shell to that of C. (Flaventia) ovalis it is
probable that this species belongs to the sub-genus [laventia. C. (flaventia)

CLEMENTIA. 191

Ricordeana is less elongate and its postero-dorsal margin is more convex and slopes
more rapidly than in Venus sub-Brongniartiana a’ Orbigny.!

Remarks.—This is probably the species which has been recorded by some
authors from the Lower Greensand as Venus ovalis and Astarte substriata, Leymerie.
The proportions of length and height vary considerably in different specimens.

Distribution.—Lower Greensand (Perna-bed) of Atherfield. Atherfield Beds
of Hast Shalford, Redhill, and Peasmarsh. Hythe Beds of Hythe, Lympne, and
Pulborough.

CuEMEntTIA (FLAvENTIA) ovALIS (Sowerby), 1827. Plate XXIX, figs. 19—26.

1827. Venus ovauis, J. de C. Sowerby. Min. Conch., vol. vi. p. 129, pl. dixvii,
fig. 1 (not fig. 2).

1850. — — A. ad Orbigny. Prodr. de Pal., vol. ii, p. 159.

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 231 (not from the
localities given).

1870. — — F. Stoliczka. WPaleont. Indica, Cret. Fauna S. India, vol.

iui, p. 160.

Non 1840. - — A. Goldfuss. Petref. Germ., vol. ui, p. 247, pl. cli, fig. 5
(Venus subovalis, VOrbigny, 1850).
— 1846. -- — A. E. Reuss. Die Verstein. der bohm. Kreideformat., pt. 2,
p. 21, pl. xxxiv, fig. 22.
— 1847. -— — J. Miiller. Petref. der Aachen. Kreidef., pt. 1, p. 24.
— 1870. -- — H. Credner. Zeitschr. d. deutsch. geo]. Gesellsch., vol. xx,
pelle
— 1884. Cyrnerra ovauis, E. Holzapfel. Ibid., vol. xxxvi, p. 464, pl. vii, figs. 2—4.
— 1888. — — G. Miiller. Jahrb. d. k. preussisch. geol. Landesanst. fiir
1887, p. 427.
— 1889. — — Fi. Holzapfel. Die Mollusk. Aachen. Kreide (Paleon-

tographica, vol. xxxv), p. 169, pl. xiii,
figs. 11—15.

—_—- — VeNus — A. Fritsch. Stud. im Gebiete der béhm. Kreideformat.,
iv, Teplitz. Schicht., p. 80, fig. 69.

— 1898. Cyrnrrra — G. Miiller. Mollusk. d. Untersen. v. Braunschweig u.
Ilsede, p. 66. pl. ix, fig. 15.

— 1901. ~- — F. Sturm. Jahrb. d. k. preussisch. geol. Landesanst. fiir

1900, vol. xxi, p. 83.

Description.— Shell elongate-oval, of moderate convexity, considerably inequi-
lateral. Antero-dorsal margin rather long, concave. Anterior margin rounded,

1 Leymerie, ‘Mém. Soe. géol. de France,’ ser. 2, vol. v (1842), pp. 5, 25, pl. v, fig. 7; d’Orbigny,
‘Pal. Frang. Terr. Crét.,’ vol. iii (1845), p. 432, pl. eeclxxxii, figs. 3—6; Pictet and Campiche, ‘Terr.
Crét. Ste. Croix’ (1865), p. 168, pl. exi, fig. 1.

192 CRETACEOUS LAMELLIBRANCHIA.

passing gradually into the considerably curved ventral margin. Postero-dorsal
margin long, convex. Posterior margin short, rounded. _Umbones prominent,
pointed, with a considerable anterior curvature. Lunule ovate, faintly limited.

Ornamentation consists of growth-rings and (in well-preserved specimens) of
numerous small, regular, concentric ribs. Pallial sinus deep, ascending, with
rounded end.

Hinge: In the right valve the anterior and median cardinals are strong, and
diverge below the umbo; the posterior cardinal is long, oblique, curved, and
divided into two parts of which the anterior is shorter than the posterior. In
the left valve the anterior and median cardinals are strong and diverge below
the umbo; the posterior cardinal is laminar and very oblique.

Measurements :

(1) (2) (3) (4) (5) (6)
Length . 44 . 40 . 37 . 34 . 382 . 30 mm.
Height: . 33" al” 32 20° ie ws 8 oo Lea

(1—6) Blackdown.

Affinities.—The form from the Aachen Greensand which was referred to this
species by Goldfuss and others possesses an anterior lateral tooth.

Remarls.—In Sowerby’s figure the lunule projects more than in any specimen
which I have seen, but in other respects the examples from Blackdown agree with
that figure.

Type.—The type came from Blackdown, but cannot now be found.

Distribution.—Upper Greensand (zone of Schlaubachia rostrata) of Blackdown!
Recorded by Jukes-Browne from the Upper Greensand of Devizes.

Genus—Catiuista, O. A. LD. Moérch, 1853.
(‘ Catalog. Conchyl. de Yoldi,’ 1, p. 27.)

CaLLista PLANA (Sowerby), 1813. Plate XXX, figs. 1—6.
1813. Venus pranus, J. Sowerby. Min. Conch., vol. i, p. 58, pl. xx, lower figures.
1854, Cyruerna pLaNna, J. Morris. Cat. Brit. Foss., ed. 2, p. 201.
21845. Venus prana, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 447, pl.
ecelxxxvi, figs. 1—3 (? partim).

' The type of Venus submersa, Sowerby, from the Upper Greensand of Pinhay, cannot be found.
I have seen no specimen which could be referred to that species. Barrois, however, records it from
the Upper Greensand of Lulworth. J. de C. Sowerby, ‘Trans. Geol. Soc.,’ ser. 2, vol. iv (1836), pp. 242,
342, pl. xvii, fig. 4; d’Orbigny, ‘ Prodr. de Pal.,’ vol. ii (1850), p. 159; Morris, ‘ Cat. Brit. Foss.,’ ed. 2
(1854), p. 231; Stoliczka, ‘ Palweont. Indica, Cret. Fauna 8. India,’ vol. iii (1870), p. 161 (Caryatis)
Barrois, ‘ Terr. Crét. Supér, de !Anglet. et de l’Trelande ’ (1876), p. 90.

CALLISTA. 193

1850. Venus puana, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 159.

1865. — — FE. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser.
4), p. 190.
1867. — . Guéranger. Album Paléont. de la Sarthe, p. 13, pl. xvii,
fig. 11.
1868. — — A. Briart and F. L. Cornet. Meule de Bracquegnies (Mém.

cour. et Mém. des Sav.
étrangers, vol. xxxiv), p. 72,

pl. vi, figs. 3—5.

? Non 1846. Venus prana, A. H. Reuss. Die Verstein. der bshm. Kreideformat., pt. 2,
p- 21, pl. xli, fig. 14.
? — 1879. Cyruerea (Caryatis) pLana, J. F. Whiteaves. Mesoz. Foss., vol. i (Geol.
Surv. Canada), p. 149,
pl. xvii, fig. 14.

Description.—Shell oval, sometimes more or less triangular, rounded, moderately
convex, considerably inequilateral; length greater than height. Antero-dorsal
margin long, concave. Anterior part of valve more or less produced, with
rounded margin. Ventral margin forming a considerable curve. Posterior margin
short, rounded or slightly truncate. Postero-dorsal margin convex, much longer
than the antero-dorsal margin. Umbones rather prominent, pointed, close
together, curved anteriorly. Lunule long, cordiform, distinctly limited.
Escutcheon not defined. Ornamentation consists of small concentric ridges, with
stronger growth-ridges at intervals. Fine radial ribbing is occasionally seen in
the posterior part of well-preserved specimens. Pallial sinus fairly large, angular
or sub-angular, slightly ascending.

Hinge: In the right valve the anterior and median cardinals are nearly
vertical, slightly diverging, and separated dorsally, the posterior cardinal is
oblique, long and divided, its posterior part is much longer than the anterior part,
and the latter nearly meets the anterior cardinal under the umbo; in front of the
cardinal teeth there is a shallow, elongate pit with slightly raised upper and lower
margins. In the left valve the stout anterior and median cardinals diverge from
under the umbo, the anterior tooth being nearly vertical; there is a long slender,
oblique posterior cardinal, and an elongate, ridge-like anterior lateral tooth, which
is grooved or corrugated.

Measurements :

(1) (2) (3) (4) (5) (6) (7) (8) (9)
Length . 72 69 63 62 54 52 48 44 35 mm.
Height . 6: be 6 6os,)6 hl CC AGS 48.lC 4 TCD ti,

(1—9) Blackdown.

Afjinities.—Specimens from Senonian deposits of Europe have been referred to

194 CRETACEOUS LAMELLIBRANCHIA.

Venus planus, Sowerby, by several authors;' and so far as I can judge from the
few figures which have been published, they seem to differ but little from
Sowerby’s species. The example from Aachen figured by Goldfuss agrees closely
with specimens from Blackdown except that the lunule projects more at the
margin. Holzapfel has compared Aachen with Blackdown specimens, and
confirms Goldfuss’s identification. The example figured by d’Orbigny®* differs
in having a large and deep escutcheon.

Specimens from the Trichinopoli Group (near the base of the Ariyalir Group)
were identified by Stoliezka® with Venus planus.

The absence of a channel under the anterior right cardinal, and the occurrence
of fine radial ornamentation connect this species with Callista. The pallial simus,
however, resembles that of Pitaria. The anterior lateral tooth in the left valve is
much less prominent, and the corresponding pit in the right valve much smaller
and shallower than in either Callista or Pitaria. This species is the type of the
section or sub-genus Callistina, Jukes-Browne.*

Remarks.—This is a common fossil at Blackdown. The variations seen
consist in the proportion of height to length, the more or less triangular or oval
outline, and the more or less produced anterior part of the shell.

T'ype.—From Blackdown; in the British Museum.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown
and Haldon. Recorded by Jukes-Browne from the Upper Greensand of Devizes,
the Isle of Wight, ete.

Pamily—CARDIIDAN, Lamarck.

(renus—Prorocarnia, H. Beyrich, 1845.
(‘ Menke’s Zeitschr. f. Malakozool.,’ p. 17.)

PROTOCARDIA ANGLICA, sp. nov. Plate XXX, figs. 7 a,b; Plate XXXI, fig. 1.

Description.—Shell large, convex, with flattened sides, subquadrate, moderately

1 Goldfuss, ‘ Petref. Germ.,’ vol. ii (1840), p. 238, pl. exlvii, fig. 4; Miller, ‘ Petref. der Aachen.
Kreidef.,’ (1847), pt. 1, p. 25; Drescher, ‘ Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. xv (1863), p.
344; Brauns, ‘ Zeitschr. f. d. gesammt. Naturwiss.,’ vol. xlvi (1876), p. 368; H. Schréder, ‘ Zeitschr.
d. deutsch. geol. Gesellsch.,’ vol. xxiv (1882), p. 275; Holzapfel, ‘Die Mollusk. Aachen. Kreide’
(‘ Paleontographica,’ vol. xxxv, 1889), p. 171, pl. xiii, figs. 16—18; Vogel, ‘ Holliindisch. Kreide’
(1895), p. 42.

2 D’Orbigny subsequently separated the Senonian form under the name Venus subplana, * Prodr.
de Pal.,’ vol. ii (1850), p. 237. See also V. Renauwxiana, V@Orbigny, ibid., p. 194.

3 Stoliezka, ‘ Paleont. Indica, Cret. Fauna 8. India,’ vol. iii (1870), pp. 151, 160, 169, pl. vii, figs.
1—4.

* Proc. Malacol. Soe., vol. viii (1908), p. 156.

PROTOCARDIA. 195

inequilateral, length and height nearly equal. Antero-dorsal margin nearly
straiglit. Anterior margin convex, curving rapidly to join the ventral margin,
which is moderately or slightly convex. Posterior margin truncated, forming
angles with the ventral and postero-dorsal margins. Umbones large, curved
forwards, with a sharp carina extending in a curve to the postero-ventral angle
and limiting the flattened, steeply-sloping posterior area, the dorsal portion of
which is concave. Shell depressed in front of the umbones.

Ornamentation: Sides of shell nearly smooth except for numerous, very small,
concentric ribs which are separated by flat interspaces. The posterior area 1s
radial ribs.

covered, except near the postero-dorsal margin, by 12 strong

Measwrements :

(1) (2) (3)
Length. 80 : 76 : 46 min.
Height. 78 : 79 : NO op

(1—-3) Crackers, Atherfield.

Affinities —This species resembles P. Forbesi (Pictet and Renevier),! from the
Lower Aptian of Ste. Croix, but the umbones are less prominent, and the ribs on
the posterior area are less numerous.

It is also similar to P. timpressa (Deshayes),> but is distinguished by the
smaller curvature of the ventral margin, the greater flattening of the sides of the
shell, and the more considerable curvature of the umbones.

Distribution.—Lower Greensand (Crackers) of Atherfield.®

ProrocarpiA spHaROIDEA (Morbes), 1845. Plate XXXI, figs. 2, 5.

1845. Carpium spHmrorpium, HL. Forbes. Quart. Journ. Geol. Soc., vol. i,
p- 243. pl. il, fig. 8.
1850. -- — A. @Orbigny. Prodr. de Pal., vol. ii, p. 79.
1852. —- NECKERIANUM, F'. J. Pictet and W. Roux. Moll. Foss. Gris
verts de Genéve, pp. 424,
425, pl. xxx, fig. 3.
— _ spHHRODEUM, Pictet and Roux. Lbid., p. 546.
1854. — == J. Morris. Cat. Brit. Foss., ed. 2, p. 193.
1 «Poss. Terr. Aptien’ (‘Matér. Pal. Suisse,’ ser 1, 1856), p. 79, pl. viii, fig. 4; Pictet and
Campiche, ‘Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4, 1866), p. 261.
2 D’Orbigny, ‘ Pal. Frang. Terr. Crét.,’ vol. iii (1844), p, 20, pl. cexl; Pictet and Campiche,
op. cit., p. 249.

3 Some specimens of Protocardia from the Lower Greensand of Atherfield were referred by Forbes
to Curdium peregrinorsum, VOrbigny, but that identification was doubted by Pictet and Campiche.
The specimens at present available are insuflicient for exact determination. See Forbes, ‘ Quart.

Journ. Geol. Soc.,’ vol. i (1845), p. 243.

196 CRETACEOUS LAMELLIBRANCHIA.

1856. Carpium spHmrorpeEum, I’. J. Pictet and EB. Renevier. Foss. Terr. Aptien
(Matér. Pal. Suisse, ser. 1),
p- 77, pl. ix, fig. 3.
1866. ~ F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal. Suisse,
ser. 4), p. 260.
1871. — (? Lawvicarpium), FP’. Stoliczka. Paleont. Indica,
Cret. Fauna 8. India,
vol. iii, p. 213.
Description.—Shell stout, large, much inflated, ligher than long, slightly
inequilateral. Anterior and ventral margins rounded. Posterior margins trun-
cated, forming angles with the postero-dorsal and ventral margins. _ Umbones
prominent, with a small forward curvature, and an inconspicuous carina extending
to the postero-ventral angle and limiting the flattened postero-dorsal area.
Ornamentation consists of regular, broad, flat, concentric ribs separated by
narrow grooves. On the posterior area strong growth-ridges are present.

Measurements :

(1) (2) (3) (4) (5)
Length . 79 . 76 : 73 ‘ 69 : 47 mm.
Height . 84. . 9] : 87 : 87 : 48,

(1—5) Perna-bed, Isle of Wight.

Affinities —Pictet and Campiche state that this species is very near to
C. imbricatavium (Deshayes),! but that the posterior area is more flattened and
forms an angle with the sides of the shell; also the truncated posterior margin is
relatively longer.

Remarks.—In this species the radial ornamentation of the posterior area is
either very indistinct or quite obsolete. There is considerable variation m relative
height and length of the shell.

Type.—From the Lower Greensand (Perna-bed) of Sandown; in the Museum
of the Geological Society.

Distribution. — Lower Greensand (Perna-bed) of Atherfield and Sandown.
Recorded by Topley from the Hythe Beds of Hythe.

ProtocarpiaA, sp. Plate XXXI, fig. 4.

The collection of Upper Greensand fossils made by the late W. Vicary, which
is now in the British Museum, contains two imperfect right valves (No. L 17041)

1 D’Orbigny, ‘Pal. France. Terr. Crét.’ (1844), vol. iii, p. 18, pl. cexxxix, figs. 4—6; Leymerie,
‘Mém. Soc. géol. de France,’ ser. 2, vol. v (1842), p. 4, pl. v, fig. 2; Pictet and Campiche, ‘Terr.
Crét. Ste. Croix’ (‘ Mater. Pal. Suisse,’ ser. 4, 1866), p. 258, pl. exxi, figs. 6,7. The specimens referred
to C. imbricatarium by Forbes are examples of Unicardiwm vectense (p. 163) ; see Forbes, ‘ Quart.
Journ. Geol. Soe.,’ vol. i (1845), p. 243.

PROTOCARDIA. 197

from Haldon, which resemble in shape the higher forms of P. spheroidea, but the
umbones are narrower and more curved, and the carina is more distinct.
Better specimens are needed before a satisfactory comparison can be made. ‘The
occurrence of P. sphxroidea in the Upper Greensand (zone of Pecten asper) of
Wiltshire has been recorded by Mr. Jukes-Browne.

Prorocarpia, sp. Plate XXXI, fig. 5a, b.

Description.—Shell globose, with rounded outline, shghtly mequilateral, height
and length nearly equal. Umbones low, curved anteriorly. The posterior
part of the shell (except near the postero-dorsal margin) is ornamented with from
ten to twelve strong radial ribs; the remainder of the shell bears numerous, small
concentric ribs.

Affinities.—This species resembles P. peregrinorsa (d’Orbigny),' but the area
with radial ribs is relatively larger, and the concentric ribs are finer.

Remarks.—The only specimens seen are two in the Museum of Practical
Geology and two in Mr. Lamplugh’s collection.

Distribution.—Speeton Clay (zone of Belemnites lateralis, D, 4) of Speeton.*

ProvocarpiA Hiniana (Sowerby), 1813. Plate XXXI, figs. 6 a—c; Plate XXXII,

>

1813. Carprum Hrnuanum, J. Sowerby. Min. Conch., vol.i, p. 41, pl. xiv
(upper figure).

1819. — — Lamarck. Hist. nat. Anim. sans Vert., vol. vi, p. 20.
1837 = — A. Goldfuss. Petref. Germ., vol. ii, p. 220, pl. exliv,
fig. 4.
= -- F. Dujardin. Mémn. Soc. géol. de France, vol i
p- 224.
184.0. — H. B. Geinitz. Char. d. Schicht. u. Petref. des

siichs. Kreidegeb., pt. 2, p. 53.

184 F. A. Rémer. Die Verstein. d. nord-deutsch.
Kreidegeb., p. 71.
1842. — Requentanum, P. Matheron. Catal. Foss. du Départ. des

Bouches-du-Rhone, p. 157,
pl. xviii, fig. 6.

1 «Pal. Frane. Terr. Cret.,’ vol. iii (1844), p. 16, pl. cexxxix, figs. 1—3,; Pictet and Campiche,
‘Terr. Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser. 4, 1866), p. 254, pl. exxi, figs. 1, 2.

2 Internal casts of a globose and nearly equilateral “ Cardium” (perhaps Protocardia), from the
Spilsby Sandstone of Donnington, are in the Sedgwick Museum.

26

198

1845.

1844.

1845.
1846.

1864.

1866.

? 1867.

1873.

CRETACEOUS LAMELLIBRANCHIA.
Carpium Hiiianum, H. B. Geinitz. Die Verstein. von Kieslingswalda,
p- 13, pl. ii, figs. 10, 11.

= A. WOrbigny. Pal. Frang. Terr. Crét , vol. iii, p.

27, pl. cexlii.

Menke’s Zeitschr. f. Malakozool., p. 18.
Die Verstein. der bohm. Kreide-

format., pt. 2, p. 22, pl. xlv,

fig. 2.

Grundr. d. Verstein., p.

Prorocarpia Hitiana, EH. Beyrich.
A. EH. Reuss.

H. B. Geinitz. 421,
pl. xix, fig. 4.

Carpium Hivianum, Lf. Forbes. Trans. Geol. Soc., ser. 2, vol. vii, p. 146.

A. d’Orbigny. Prodr. de Pal., vol. ii, p. 162.

Prorocarpia Hinuana, H. B. Geinitz.

Das Quadersandst. oder Kreidegeb.
in Deutschland, p. 154.

Carpium Hitianum, F. Rimer. Kreidebild. v. Texas, p. 49, pl. vi, fig. 12.

Prorocarpia Hiniana, H. G. Bronn. Lethwa Geogn., vol. ii, p. 302,
pl. xxx, fig. 12.

Kreideschicht. i. d. Ostalpen, p. 145,
pl. xxviii, fig. 19.

Hiztianum, J. Morris. Cat. Brit. Foss., ed. 2, p. 192.

Provocarpra Hrnwana, R. Drescher.

Carpiom Birrons, A. EH. Reuss.

Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xv, p. 346,
Canpium (ProrocarpraA) Hitiana, K. A. Zittel. Die Bivalv. d. Gosaugeb.,
I, p. 42 [146], pl. vii, figs. 1, 2.
= Hituanum, F. J. Pictet and G. Campiche. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser. 4),
pp. 268, 273.
Aus dem Orient, I, p. 91.
Album Paléont. de la Sarthe, p. 15,
pl. xx, figs. 3, 11.
A. Briart and F. L. Cornet.
(Mémn. cour. et Mém. des Sav. étrangers, -

O. Fraas.
EH. Guéranger.

Meule de Bracquegnies

vol. xxxiv), p. 66, pl. vii, figs. 4, 5.
Provocarpia Hitxana, fF’. Rimer. Geol. v. Oberschles., p. 334, pl. xxvi,

fig. 2.

Palzont. Indica, Cret. Fauna 8.
India, vol. iii, pp. 209, 219, pl. xii,
figs. 8—10, pl. xiii, figs. 1—3.

H. B. Geinitz. Das Hibthalgeb. in Sachsen
(Paleontographica, vol. xx,
pt. i), p. 230, pl. 1, figs. 11, 12.
var. MoaBITIcuM, L. Lartet. Ann. Sci. géol.,
iH, p. 53, pl. xu, fig. 9.

Prorocarpium Hituanum, I’. Stoliczka.

CarpIuM
vol.
Zeitschr. f. d. gesammt. Naturwiss.,
vol. xlvi, p. 266.
Stud. im Gebiete der bbhm. Kreide-
format., ii, Weissenberg. u. Malnitz.
Schicht., p. 112, fig. 64.

Prorocarpia Hiuuana, D. Brauns.

Provrocarpium Hiuianum, A. Fritsch.

PROTOCARDIA. 199

? 1878. Prorocarptum Hinianum, O. Fraas. Aus dem Orient. II Geol. Beobacht.
am Libanon, p. 70.
1882. Carprum (Prorocarprum) Hittanum, P. de Loriol. Gault de Cosne, p.
69, pl. viii, fig. 17.
1884. Prorocarprum Hittanum, J. F. Whiteaves. Mesoz. Foss. (Geol. Surv.
Canada), vol. i, p. 228,
pl. xxx, fig. 5.
? — Carprum (Protocarpra) Hrttanum, C. E. Hamlin. Mem. Mus. Comp.
Zool., vol. x, No. 3, p. 50.
1893. Prorocarprum Hintanum, R. Michael. Zeitschr. d.deutsch.geol. Gesellsch.,

vol. xlv, p. 232.

1897. a = A. Fritsch. Stud. im Gebiete der bohm. Kreide-
format., vi, Chlomek. Schicht.,
p. 52.

= — — Rk. Leonhard. Kreidef. in Oberschles. (Pal-
eontographica, vol. xliv), p. 28.
1898. — — A. Fritsch. Stud. im Gebiete der bohm. Kreide-
format., ii, Iserschicht., p. 98.
1901. Provocarpia Hrnxnana, F. Sturm. Jahrb. d. k. preussisch. geol. Landes-
anst. fiir 1900, vol. xxi, p. 79.
1902. — — A. Quaas. Kreidebild. in der libysch. Wiiste
(Paleontographica, vol. xxx, 2),
p. 218, pl. xxiv, fig. 18.
1904. — — R. Fortau. Bull. Instit. Egyptien, ser. 4, no. 4,
p. 331.
= = — var. UMKWELANENSIS, R. Etheridge, jun. Second
Rep. Geol. Surv. Natal and
Zululand, p. 79, pl. i, fig. 16.
1906. — — var., H. Woods. Cret. Fauna of Pondoland (Ann.
8. African Mus., vol. iv), p. 307,
pl. xxxvii, fig. 6.

Description.—Shell convex, with flattened posterior slope, nearly equilateral ;
outline more or less sub-quadrate, rounded, sometimes nearly oval; usually <
little higher than long, but rarely with the height and length equal Anterior
margin either fairly convex and forming a rounded angle with the antero-dorsal
margin, or very conyex and passing almost gradually into the antero-dorsal
margin. Anterior margin passes gradually into the ventral margin, which may be
considerably convex, but is usually only slightly convex, with its posterior part
nearly straight and forming a more or less well-marked angle with the posterior
margin. The latter is truncated, slightly convex, and forms an obtuse angle with
the postero-dorsal margin. Umbones of moderate size.

Ornamentation consists (except on the posterior part of the shell) of numerous,
very regular, rounded, concentric ribs separated by narrow furrows; these ribs
become smaller or nearly obsolete near the antero-dorsal margin. On the posterior

200 CRETACEOUS LAMELLIBRANCHIA.

slope of the shell, and sometimes for a short distance in front of it, are from 10 to 15
(usually 12 or 15) strong, more or less angular ribs, separated by broad furrows,
both being crossed by well-marked growth-ridges. Sometimes some of these ribs
are divided at their summits by a narrow, longitudinal groove. The ribs become
rather smaller dorsally and are absent near the postero-dorsal margin. Internal
margins of valves smooth, except the posterior part with radial ribs, which is
serrate.
Measurements :
Gd) @) (@) ( £6) (©) (@ (8) (9 (0) (11) (12)
Length 51 48 44 44 43 41 38 36 36 32 27 19 mm.
Height 47 47 44 42 41 39 36 36 34 295 26 18 ,,
(1—12) Blackdown.

Affinities—Although this species has a very wide geographical distribution
and a long range in time, yet the principal variations seen in specimens found
at different horizons and in different kinds of sediment consist in the number and
coarseness of the concentric ribs. The modifications do not appear to be more
than varietal, and such as would be found at the present day in examples of a widely
distributed species.

In the example from the Cenomanian figured by d’Orbigny the shell is rather
higher and the ornamentation coarser than in specimens from Blackdown, but in
the latter respect it agrees with examples found by the late C. J. A. Me¥er in the
Cenomanian of South Devon. One specimen from the Cenomanian of Sarthe,
shown in Guéranger’s photographic illustrations, agrees in its ornamentation with
Blackdown examples.

The Cenomanian form figured by Rémer (1870), and the examples from
higher horizons figured by Geinitz (1843) and by Goldfuss agree closely with Black-
down specimens. Coarser ribbing is found in specimens from the Gault of Cosne,
showing that that character is not limited to examples from horizons above the
Blackdown Greensand.

Protocardia bifrons (Reuss) is more rounded than P. Hillana, but does not seem
to be specifically distinct.

OCardium marticense, Matheron, and C. Requienianum, Matheron, were regarded
by d’Orbigny and by Zittel as synonyms of P. Hillana.

Specimens from the Trichinopoli Group of Southern India were identified with
P. Hillana by Forbes and by Stoliezka, who stated that they were unable to draw
any line of separation between the Indian and European examples. |The concen-
tric ribbing is coarser in most of the Indian forms, and im some the smooth inner
portion of the posterior area is relatively larger than in specimens from Blackdown.!

' See Stoliezka’s fig. 10a.

CARDIUM. 201

P. delicatula, Stoliezka,' and P. pondicheriense (d’Orbigny),’ are allied to
P. Hillana.

P. biseriata (Conrad),® from Syria, possesses coarse concentric ribs, and is
regarded by Blanckenhorn as a variety of P. Hillana.

Remarks.—Examples of this species are common at Blackdown, but probably on
account of the uniformity of the conditions under which they lived, do not show
any very striking variations.

There are some differences in the proportion of length and height ; usually the
former exceeds the latter slightly, but occasionally the two are equal. The outline
of the shell is sometimes oval, but more usually subquadrate. The radial ribs vary
in number from 10 to 15, and sometimes the area with these ribs is continued for a
short distance in front of the posterior slope.

The number of concentric ribs in 10mm. (measured between 34mm. and
44mm. from the umbo) varies from 15 to 19.

T'ype.—From Blackdown, in the British Museum.

Distribution—Upper Greensand (zone of Schlaenbachia rostrata) of Blackdown,
Haldon, Whitecliff (South Devon), Peak Hill near Sidmouth, Devizes, and
Ventnor. Cenomanian of Dunscombe. Recorded by Jukes-Browne from the

Chloritic Marl of the Isle of Wight.

Genus—Carpium, Linneus.

(‘Syst. Nat.’ ed. 10, 1758, p. 678; ed. 12, 1766, p. 1121.)

Carpium Ispersoni, Morbes, 1845. Plate XXXII, figs. 7—10.

1845. Carpium Issersont, 1. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 248,
pl. u, fig. 9.

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 192.
1856. . — F. J. Pictet and E. Renevier. Foss. Terr. Aptien

(Matér. Pal. Suisse, ser. 1), p. 78,
pl. ix, figs. 1, 2.
1866. — = F. J. Pictet and G. Campiche. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser. 4),
p. 262.
1871. — -- (Lavicarpium), F. Stoliczka. Paleont. Indica, Cret.
Fauna 8S. India, vol. iii, p. 213.

1 «Palwont. Indica, Cret. Fauna S. India,’ vol. iii (1871), p. 220, pl. xiii, fig. 8.

2 Stoliczka, ibid., p. 220, pl. xii, figs. 4—7.

3 * Official Report U.S. Exped. Dead Sea, ete.,’ by W. F. Lynch (1852), p. 216, pl. vi, figs. 38, 39
(non 40); R. B. Newton, ‘Geol. Mag.,’ (1898), p- 400, pl. xv, fig. 11. P. Hillana var. typica,
M. Blanckenhorn, ‘ Beitr. zur Geol. Syriens : Kreidesyst. in Mittel u. Nord-Syriens ’ (1890), p. 89.

202 CRETACEOUS LAMELLIBRANCHIA.

Description.—Shell small, inflated, oval, a little higher than long, shghtly
inequilateral. Anterior margin rounded, passing gradually into the convex
ventral margin. Posterior margin subtruncate, higher than the anterior margin.
Umbones prominent, with a faint carma extending to the postero-ventral extremity
and forming the limit of the flattened postero-dorsal area. Margins of valves
serrate.

Ornamentation consists of numerous small, slightly-raised radial ribs separated
by narrow grooves; anteriorly the ribs become gradually smaller and are absent
or indistinct near the antero-dorsal margin; on the postero-dorsal area the ribs
are stronger and the grooves broader than elsewhere, and the anterior margins of
these ribs are sometimes serrate. In well-preserved specimens faint concentric
linear ridges are seen.

Measurements :

(1) (2) (3) (4) (5)
Length . 17 P Sy Or 14. : 10°5 mm.
Height . 18 : ier) 15 : (4-55 1] e

(1—5) Crackers, Atherfield.

Affinities.—See C. Cottaldinwm (p. 203).

In form C. I[bbetsoni resembles C. Raulinianum, dOrbigny,’ but the latter is
distinguished by its broader grooves which bear pointed projections.”

In the specimens figured by Pictet and Renevier from the Aptian of the Perte
du Rhéne the umbones are more prominent than in English examples of
C. Ibbetsoni, but Pictet and Campiche, who were able to compare examples from
Atherfield with those obtained from the Perte du Rhdéne, felt no doubt as to
their specific identity.

Type.—From Atherfield, in the Museum of the Geological Society.

Distribution.—Lower Greensand (Crackers) of Atherfield.

1 «Pal. Frane. Terr. Crét.,’ vol. iii (1844), p. 25, pl. cexlii, figs. 7—11.

2 CO. Raulinianum is recorded by Morris from the Lower Greensand of the Isle of Wight, and by
Topley from the Athertield Beds of Peasmarsh and Shalford. Specimens from the Atherfield Clay
were referred to CO. subhillanwm, Leymerie, by Forbes, but that identification was regarded as doubtful
by Pictet and Campiche ; the form of the shell cannot be made out satisfactorily, but the ornamenta-
tion resembles that of C. Ibbetsoni. An internal cast from the Lower Greensand of Upware was
referred with doubt to C. subhillanum by W. Keeping (‘ Foss. Neoc. Upware and Brickhill, 1883,
p- 119) ; the specimen is now in the Sedgwick Museum, Cambridge, and seems to me insufficient
for determination. A specimen with radial ribs, from the Lower Greensand of Maidstone, was named
Cardium Benstedi by Forbes, but was too imperfect for figuring ; the type is in the Museum of the
Geological Society (No. 2124) ; no other specimen has been seen. Forbes, ‘ Quart. Journ. Geol. Soc.,’
vol. 1 (1845), p. 244; Pictet and Campiche, ‘ Foss. Terr. Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser 4,
1866), p. 267.

CARDIUM. 203

Carpium Corranpinum, @’Orbigny, 1844. Plate XXXII, fig. 11 a—e.
1844. Carpium Corrauptnum, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ili,
p. 22, pl. cexlii, figs. 1—4.
1850. = — @ Orbigny. Prodyr. de Pal., vol. 11, p. 79.
1866. — — F. J. Pictet and G. Campiche. Terr. Crét. Ste.
, Croix (Matér. Pal. Suisse, ser. 4),
p. 246, pl. exviii, figs. 1, 2.

1871. — = F. Stoliczka. Paleont. Indica, Cret. Fauna 8S.
India, vol. iii, p. 212.

1883. — - W. Keeping. Foss., etc., Neoc. Upware and Brick-
hill, p. 118, pl. vi, fig. 4.

1884. — — O. Weerth. Die Fauna des Neocom. im Teutoburg.

Walde (Paleont. Abhand1., vol. ii),
p- 44, pl. ix, fig. 3.
oo _ OxpriincHusANum, Weerth. Ibid., p. 44, pl. ix, fig. 4.

1895. — Corratpinum, G. Maas. Zeitschr. der deutsch. geol. Gesellsch.,
vol. xlvu, p. 263, pl. vii, figs. 2, 3.
1900. — — A. Wollemann. Die Biv, u. Gastrop. d. deutsch. u.

holliind. Neocoms (Abhandl. d.
k. preussisch. geol. Land., Nn. F.,

pt. 31), p. 107.

Description.—Shell oval, inflated, shghtly imequilateral, rather higher than long.
Anterior and ventral margins rounded. Posterior margin more or less truncated.
Umbones rather high, sharp, curved inward and forward, with an indistinct carina.

Ornamentation consists of numerous, small, regular, radial ribs, which are
rather more prominent on the posterior area than on the sides of the shell.

Measurements ¢

Length : ‘ : - 24 mm.
Height : : , : 25°59 ,,
Upware.

Affinities. —This species closely resembles C. Lbbetsoii, but differs in having the
posterior area less flattened and the outline of the shell more rounded. The
English specimens of CU. Cottaldinwm are larger than those of C. /bbetsoni, but are
not sufficiently numerous or well-preserved for exact comparison.

In C. Cottaldinum the shellis relatively higher than in C, Voltzi, Leymerie.'

C. landeronense, de Loriol,’ appears to be closely related to C. Cottaldinum.

Type.—D’Orbigny’s specimens came from the Neocomian of Wassy (Haute-

! For references see Pictet and Campiche, ‘Terr. Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser. 4,
1866), p. 247.
2 P. de Loriol and V. Gilli¢ron, ‘ Urgonien Infér. de Landeron’ (1869), p. 14, pl. i, fig. 12.

204. CRETACEOUS LAMELLIBRANCHIA.

Marne), Brillon (Meuse), St. Sauveur and Auxerre (Yonne). The specimens
figured by Keeping are in the Sedgwick Museum.
Distribution.—Lower Greensand of Upware.!

Carpium, sp. Plate XXXII, fig. 12 a, b.

Internal casts of a globose form of Cardium occur in the Lower Greensand of
Seend and Faringdon. On one specimen (No. 21272, Museum of Practical
Geology) a portion of the shell is preserved, and its ornamentation resembles that
of C. Ibbetsoni and C. Cottaldinum. The form of the shell seems to be rather more
like that of C. [bbetsoni than of OC. Cottaldinum.

CarpDIUM, spp.

Specimens of Cardium from the Cenomanian of Dunscombe, South Devon, were
referred by C. J. A. Meyer to C. alternans, Reuss, and C. alutacewn, Goldfuss.

Better preserved specimens are needed before these determinations can be con-

firmed.

Carpium tuRONIENSE, Woods, 1897. Plate XXXII, figs. 13—15.

1897. Carprum turoniensE, H. Woods. Quart. Journ. Geol. Soc., vol. lili, p. 389,
pl. xxvii, figs. 20—22.

Description.—Shell small, oval, higher than long, equilateral, much inflated,
postero-dorsal part compressed. Umbones prominent, with a considerable anterior
curvature. Ornamentation consists of many strong radial ribs. Length, 6 mm.;
height, 7 mm.

Affinities. —This species shows some resemblance to C. cenomanense, V Orbigny,”
but is more inequilateral owing to the much greater curvature of the umbones ;
also the ribs are less numerous, and tubercles appear to be absent from the

grooves.

T'ype.—In the Sedgwick Museum, Cambridge.

Distribution.—Chalk Rock of Cuckhamsley.

1 Some small specimens found in the Ferruginous Sands of Shanklin may perhaps be referred to
C. Cottaldinum, but they are too imperfectly preserved for exact determination.
2 «Pal. Frang. Terr. Crét.,’ vol. iii (1844), p. 37, pl. cexlix, figs. 5—9.

CARDIUM. 205

Carpium, sp. Plate XXXII, fi

ge. 16a, b.

1897. Carpium, sp. cf. cenomanense, H. Woods. Quart. Journ. Geol. Soc., vol.

liii, p. 389, pl. xxvii, figs. 23, 24.

Internal casts, similar in form to C. cenomanense, @Orbigny, are found in the
Chalk Rock of Cuckhamsley. A part of the shell is imperfectly preserved on one
specimen and is ornamented with fine radial ribs. A cast measures: height, 8 mm.;
length, 8 mm.; thickness, 7°5 mm.

Carpium, sp. Plate XXXII, fig. 17 a—e.

T'wo internal casts from the Chalk of Norwich (one of which was found by the
late T. G. Bayfield) are inthe British Museum (Nos. L 19443, 420103). The shell
is much inflated, so that the height and thickness are approximately equal; the
height is considerably greater than the length. The umbones are prominent.
‘The postero-dorsal part of the shell is flattened and shows indications of fine radial
ribs.

This species shows some resemblance to C. ventricosum, @Orbigny,' but is
relatively higher.

Sub-genus—Granocarpium, W. JZ. Gabb, 1869.
(“ Geol. Survey California,” ‘ Palzeont.,’ vol. 11, p. 266.)

Carpium (GRANocARDIUM) PRoBOSCcIDEUM, Sowerby, 1817. Plate XXXII, figs. 18, 19;

oD
Plate XXXITI, figs. 1—3.
1816. Carprra runercunara, J. Sowerby. Min. Conch., vol. ii, p. 97, pl. exlii.
(Non Cardium tuberculatum, Linneus).
1817. Carprum proposcipeum, J. Sowerby. Min. Conch., vol. 11, p. 127, pl. elvi,

fig. 1.
1835. — Genrranum, J. de C. Sowerby. Ibid. (Systematical Index), vol. vi,
p. 242.
1854. — proposcipEuM, J. Morris. Cat. Brit. Foss., ed. 2, p. 193.
= — Genrtianum, Morris. Ibid., p. 192.
1866. -- prososciprum, F’. J. Pictet and G. Campiche. Foss. Terr. Crét.

Ste. Croix (Matér. Pal. Suisse,
ser. 4), p. 269.

1 @. ventricosum is recorded from the Upper Greensand (zone of Pecten asper) of Lulworth by
Barrois (‘ Terr. Crét. Supér. de Angleterre et de I’Irelande,’ 1876, p. 92). I have not seen any
English example of that species.

27

206 CRETACEOUS LAMELLIBRANCHIA.

1866. Carpium Genvianum, Pictet and Campiche. LUbid., p. 269.

1871. — prososcrpEuM, I’. Stoliczka. Paleont. Indica, Cret. Fauna 8S.
India, vol. iii, p. 213 (Acantho-
cardium).

— — Genzianum, Stoliczka. ITbid., p. 213 (Acanthocardium).
1882. = proboscipEuM, P. de Loriol, Gault de Cosne, p. 91, pl. xi, fig. 4.
1900. — Genrianum, EL. T. Newton and A. J. Jukes-Browne. In Jukes-
Browne, Cret. Rocks of Britain,
vol. i, p. 448.

Description.—Shell stout, very convex, oval, higher than long, slightly mequi-
lateral. Anterior margin rounded; posterior margin truncated, forming an
angle with the postero-dorsal margim. Umbones prominent.

Ornamentation consists of radial ribs separated by narrow grooves; the
stronger ribs bear prominent, angular, laterally compressed tooth-like projections,
which may be rather larger near the posterior margin than elsewhere; in the
spaces between the stronger ribs are two (sometimes one or three) smaller ribs with
similar but smaller tooth-like projections. Margins of valves toothed.

Measurements :

(1) (2) (3) (4) (5)
Length 63 : 59 ; 58 P 57 : A7 mi.
Height 74 : 70 f 68 E 65 . ih

(1—5) Blackdown.

Affinities —A form from the Cenomanian was referred by d’Orbigny to
C. productum, Sowerby,! the type of which comes from the Senonian of Gosau.
This identification has been accepted by Zittel, Holzapfel and others, but not by
Pictet and Campiche, and de Loriol. The specimen figured by d’Orbigny ” is
probably an example of C. proboscideum, Sowerby, and differs from C. productum
in the distinct differentiation of the ribs into a larger series separated by smaller
series.

The differences between C. Geitianuim and C. proboscideum seem to be due
entirely to their different modes of preservation. The former is found in the
Upper Greensand of Devizes and Ventnor; the shell is absent, but the sand which
filled the interior of the shell now forms a natural cast of the exterior, showing
more or less imperfectly the character of the ornamentation; usually the spines
are represented by stumps only or are almost completely obliterated. In these
specimens the original form of the shell has been more or less considerably

: «Trans. Geol. Soc.,’ ser. 2, vol. iii (1832), p. 417, pl. xxxix, fig. 15; Goldfuss, ‘ Petref. Germ.,’
vol. ii (1837), p. 221, pl. exliv, fig. 7; Zittel, ‘ Bivalv. d. Gosaugeb.,’ pt. i (1864), p. 37, pl. vi, fig. 1;
Holzapfel, ‘‘ Die Mollusk. Aachen. Kreide ” (‘ Palesontographica,’ vol. xxxvy), p. 179, pl. xvii, figs. 1—5;
G. Miiller, ‘ Mollusk. d. Untersen. v. Braunschweig u. Ilsede’ (1898), p. 63, pl. ix, figs. 13, 14.

2 «Pal. Frang. Terr. Crét.,’ vol. iii (1844), p. 31, pl cexlvii; Guéranger, ‘ Album Paléont. de la
Sarthe’ (1867), p. 15, pl. xx, figs. 8—10.

modified by pressure.

TOUCASIA. 207

On the other hand the shell in @. proboscideum, from

Blackdown, is replaced by silica, so that both its ornamentation and original shape
are perfectly preserved.

French examples were identified by d’Orbigny! with this species, for which he
proposed the name Cardium Moutonianum since the specific name (tuberculata)
under which Sowerby originally described the species had already been used.
Sowerby, however, in the index at the end of vol. vi of the ‘ Mineral Conchology,’

had already substituted Gentianwm for the name which he originally used.

I have

not seen any specimen of C. Moutonianum, and am unable to say whether or not it
is really identical with C. Gentianum, but in d’Orbigny’s figures the difference in

the sizes of the ribs and tubercles is seen on the anterior and posterior parts of

the shell only.

C. Carolinum, @ Orbigny,® and C. inequicostatum, Matheron,* are closely related
to, and perhaps identical with, C. proboscidewm.

Types.—C. proboscideum, from the Upper Greensand of Blackdown, and

Cardita tubereulata (Cardium Gentianum), from the Upper Greensand of Devizes

>

are in the British Museum.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown,
Haldon, Devizes, and Ventnor.

Family—DICERATIDAS, Dall.

| Genus—Tovcasta, H. Munier-Chalmas, 1873.
| (‘Journ. de Conchyl.,’ ser. 3, vol. xxi, p. 74. Douvillé, ‘ Bull. Soc. géol. de France,’ ser. 3, vol. xv,
1887, p. 762.)
Tovcasta Lonspater (Sowerby), 1836. Plate XXXIII, figs. 4—6.
1836. Diceras Lonspauu, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp. 268, 338, pl. xii, fig. 4.
1850. Caprotina Lonspauir, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 109
(partim).
. 1854. Driceras Lonspauu, .J. Morris. Cat. Brit. Foss., ed. 2, p. 201.
1855. Re@gurenta Lonspauer, 8. P. Woodward. Quart. Journ. Geol. Soc.,
vol. xi, p. 53, fig. 29.
1871. — Lonspatu, F. Stoliczka. Paleont. Indica, Cret. Fauna

S. India, vol. i, p. 233.

p. 162.

2 Op. cit. (1844), p. 29, pl. cexlv.
8 «Catal. Foss. des Bouches-du-Rhéne ’ (1842), p. 157, pl. xviii, figs. 3, 4.

208 CRETACEOUS LAMELLIBRANCHIA.

Remarks.—The examples of Toucasia Lonsdalei are in the condition of internal
casts in a ferruginous sandstone, so that it is difficult to compare this with other
species. The casts show a considerable amount of variation in form. D’Orbigny,
de Loriol, and Pictet and Campiche included Requienia carinata, Matheron,’ from
the Urgonian of Orgon, as a synonym of Sowerby’s Diceras Lonsdalei; but Prof.
Douvillé? and M. Paquier® think that the identity of the two forms is doubtful
and can only be determined by a careful comparison of English specimens with
internal casts of 7’. carvinata. Prof. Douvillé* suggests that there is a resemblance
between 7’. Sewnesi and T'. Lonsdalei.

Type.—The type, which is stated to have come from near Calne, cannot now
be found. The specimen from which Woodward’s outline figure was drawn is in
the British Museum, No. 88825.

Distribution.—Lower Greensand of Stock Orchard, south of Calne. Recorded

by Morris from Lockswell Heath, south-west of Calne.

Family—MONOPLEURID A, Fischer.
Genus—GyropLiEurA, H. Douvillé, 1887.
(‘ Bull. Soc. eéol. de France,’ ser. 3, vol. xv, p. 768.)
GYROPLEURA corNUCOPIm (@’Orbigny), 1847. Plate XXXITI, fig. 7 a, b.

1847. CHAMA cornucopia, A. d’Orbigny. Pal. France. Terr. Crét., vol. iii, p. 689,
pl. eeeelxiv, figs. 3—7.

1850. — a @ Orbigny. Prodr. de Pal., vol. ii, p. 170.

1868. — — FJ. Pictet and G. Campiche. Terr. Crét. de Ste. Croix
(Matér. Pal. Suisse, ser. 5), p. 7.

1871. — F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,

vol. iii, p. 234.
1887. GyropLEURA — H. Douvillé. Bull. Soc. géol. de France, ser. 3, vol.
xv, p. 771, fig. 3.

Remarks.—Two specimens from the Chloritic Marl of Dorset agree in form
with examples of G. cornucopix from the Cenomanian of Rouen (the locality

1 «Catal. Foss. des Bouches-du-Rhone’ (1842), p. 104, pl. ii, figs. 1,2; Caprotina Lonsdalii,
dOrbigny, ‘Ann. Sci. Nat. Zool.,’ ser. 2, vol. xvii (1842), p. 180; Requienia Lonsdalii, VOrbigny,
‘Pal. Franc. Terr. Crét.,’ vol. iv (1850), p. 248, pls. dlxxvi, dlxxvii; Caprotina Lonsdalii, de Loriol, in
Favre, ‘ Rech. géol. dans Savoie,’ vol. 1 (1867), p. 386, pl. C, fig. 22; Requienia Lonsdalii, Pictet and
Campiche, ‘Terr. Crét. Ste. Croix’ (‘ Mater. Pal. Suisse,’ ser. 5, 1868), p. 14, pl. elxi.

2 «Bull. Soe. géol. de France,’ ser. 3, vol. xvii (1889), p. 630.

8 «Tes Rudistes Urgoniens,’ I (‘ Mém. Soe. géol. de France,’ Paléont, XT, 1903), p. 41,
+ Op. cit., p. 632.

GYROPLEURA. 209

of the type) and with d’Orbigny’s figs. 4 and 5. The ornamentation in this
species is imperfectly known; most of the examples from Rouen are either
internal casts or haye only portions of the shell present, on which the orna-
mentation is rather indistinct. In one specimen from Dorset part of the shell
of the fixed valve is preserved; the radial ribs are not so prominent as in
G. inequirostrata, but concentric lamelle are distinct.

Distribution—Chloritic Marl of Melbury Park and Chaldon, Dorset. Recorded
by Jukes-Browne from the base of the Lower Chalk of Chard and Maiden

Newton.

GYROPLEURA INEQUIROSTRATA (Woodward), 1833. Plate XXXIII, figs. 8—13.

1833. Diceras ryequrrostratus, S. Woodward. Geol. Norfolk, p. 47, pl. v, fig. 22.
1854. CHAmMA rnmQurrosrrata, J. Morris. Cat. Brit. Foss., ed. 2, p. 194.

Description—Shell much inflated. Right valve large, oval, attached by a
considerable portion of the anterior side; umbo prominent, pointed, incurved
anteriorly. Left valve capuliform, with the umbo near the hinge-margin.

Ornamentation consists of strong, lamellar radial ribs, which are undulose
where they cross growth-rings. The ribs have strongly serrate summits and
are separated by rather broad, flat, smooth interspaces; sometimes the serrations
are replaced by numerous transverse, scale-like structures. Near the fixed part
of the right valve the ribs are more numerous than on the flank.

Measurements of fived value :

(1) (2) (3) (4)
Length : ee, ; 19 , 16 : 14mm.
Height. ees : 26 : 20 3 Sees

(1—4) Norwich.

Affinities. —G. ciplyana (de Ryckholt),'! from Ciply, differs from this species
in having the ribs more widely separated and in the presence of small ribs in
the interspaces and on the sides of the main ribs. G. russiensis (d’Orbigny)”
resembles closely G. inequirostrata and was regarded by Morris as a synonym of

the latter, but it possesses small ribs on the sides of the main ribs.®

1 «Mélanges Paléont.,’ pt. ii (1851), p. 179, pl. xu, figs. 12,13; Douvillé, ‘Bull. Soc. géol. de
France,’ ser. 3, vol. xv (1887), p. 744, pl. xxviii, fig. 11; Holzapfel, ‘ Mollusk. Aachen. Kreide’ (1889),
p. 189, pl. xix, figs. 5,6; Wollemann, ‘ Fauna d. Liineburg. Kreide’ (1902), p. 75, pl. ii, figs. 5, 6.

2 Murchison, de Verneuil, and de Keyserling, ‘G@éol. de la Russie,’ vol. ii (1845), p. 496, pl. xlii,
figs. 31—33; Douvillé, ‘ Bull. Soc. géol. de France,’ ser. iii, vol. xv (1887), p. 775, pl. xxviii, fig. 13.

3 G. Miinsteri (v. Hagenow) is probably related to @. insequirostrata, See Ravn, ‘ Mollusk. i
Danmarks Kreidtafl. I, Lamellibr.’ (1902), p. 126, pl. iv, figs. 10, 11.

210 CRETACEOUS LAMELLIBRANCHIA.

T'ype.—From Norwich; in the British Museum.
Distribution. —Upper Chalk (zone of Belemnitella mucronata) of Norwich.

GyropLeuRA, sp. Plate XXXIV, fig. 1 a—d.

Description.—Right valve inflated, attached by a large portion of the dorsal
surface. Left valve convex, subquadrate, with a pointed and incurved umbo.
Right valve ornamented with numerous, small radial ribs which bear transverse
nodes or scales. Left valve with relatively few, stout ribs bearmg strong, some-
what irregular, transverse scales or lappet-like projections.

Affinities.—The ornamentation on the right valve is finer and that on the left
valve coarser than in G. cenomanensis (d’Orbigny') ; also the transverse ornamenta-
tion of the ribs is much coarser and less regular.”

Remarks.—The portion of the right valve which was attached includes the
umbo and the neighbouring parts, whereas in most examples of Gyroplewra only
the part in front of the umbo is attached. The size of the area which was attached
is larger than usual, but in other species it is seen that that area varies considerably
in size in different examples.®

The only specimen seen was collected by Mr. Francis R. B. Wilhams.

Distribution—Upper Chalk (zone of Actinocamax quadratus) near the groyne
at Seaford.

Family—CORBULIDA, Fleming.
Genus—Corsuta, J. G. Bruguieére, 1797.

(‘ Encye. Méth.,’ Tabl. Vers., pl. 230.)

Corzceta ancunata (Phillips), 1829. Plate XXXIV, figs. 2—5.

1829. Tsocarp1a anauxara, J. Phillips. Geol. Yorks., p. 94, pl. ii, figs. 20, 21
(ed. 3, 1875, p. 252).

1841. — —_ F. A. Romer. Die Verstein. d. nord - deutsch.
Kreidegeb., p. 70.

1854. — -- J. Morris. Cat. Brit. Foss., ed. 2, p. 204.

1 «Pal. Franc. Terr. Crét.,’ vol. iv (1850), p. 261, pl. dxev, figs. 1—4.

2 Douvillé, ‘Bull. Soc. géol. de France,’ ser. 3, vol. xv (1887), p. 771, pl. xxviii, fig. 7.

8 In a specimen figured by Griepenkerl the surface of attachment is unusually large; ‘Senon vy.
Konigslutter’ (‘ Paleont. Abhandl.,’ v, 1889), pl. vil, fig. 3.

CORBULA. 211

1865. Isocarpra? anauxara, I’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse,
ser. 4), p. 240.
1871. Isocarpra aneuuata, F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. ii, p. 194.
1877. Isocarpia? aneunara, G. Bohm. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxix, p. 241.
1889. Isocarpria anautara, G. W. Lamplugh. Quart. Journ. Geol. Soc., vol. xlv,
p. 616.

1900. — — A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.
hollind. Neocoms (Abhandl. d. k.
preussisch. geol. Land., N. F., pt.
31), p. 114.

1905. Corsuta (Isocarpra) aneunara, H. Harbort. Fauna d. Schaumberg-Lippe-

schen Kreidemulde (Ibid.,
pt. 45), p. 81.

1906. Isocarpi1a aneutatra, A. Wollemann. Die Biv. u. Gastrop. nord-deutsch.
Gaults (Jahrb. d. k. preussisch.
geol. Land., fir 1906, vol. xxvi1),
p. 277.

Description—Shell with sub-quadrate outline, rounded, occasionally sub-
triangular, very convex, equivalve, more or less considerably inequilateral; length
ereater than height. Anterior part produced, rounded; ventral margin slightly
curved; posterior margin truncate, slightly convex, somewhat oblique, forming
angles with the ventral and dorsal margins. Postero-dorsal margin sloping
ventrally. Umbones moderately large, curved inward and more or less considerably
forward, with a carina extending to the postero-ventral angle, cutting off a large,
flattened postero-dorsal area. ‘lhe part of the valve in front of the carina is
regularly convex. Lunular region depressed.

Ornamentation consists of fine concentric strie.

Measurements :

(2) (8) (4) (®) (6) (7)
ease eel = OS. OS Gl. OO). 680 06 45 mm.
Hecht sO UnwepoL .« off . o . 456 . 41 . 40 ,;
(1—7) Speeton.

Affinities —This species shows some resemblance to C. gaultinu (see p. 214), but
is more nearly quadrate in outline, relatively longer, of larger size, and without
distinct ribs.

C. angulata is fairly common in the Speeton Clay, but no specimen showing the
hinge appears to have been found, so that the generic position assigned to this
species by Phillips was presumably based on the external character of the shell.
Pictet and Campiche thought that it probably belonged to Cyprina. Wollemann
states that it is most likely a Corbula, and Harbort, who has seen the hinge,

212

CRETACEOUS LAMELLIBRANCHIA.

definitely refers it to that genus; if this view of its position is confirmed it will be

necessary to substitute a new name, since angulata had been previously used by
Lamarck for a species of Corbula from the Eocene.

Distribution.—Speeton Clay (zones of Belemiites jaculum and B. brunsvicensis)

of Speeton.!

CoRBULA STRIATULA, Sowerby, 1827. Plate XXXIV, figs. 6—12.

1827.
1846.
1850.
1854.

1858.

1864.

Non 1840.

CorpuLa srriaruLa, J. de C. Sowerby. Min. Conch., vol. vi, p. 139, pl.

dixxil, figs. 2, 3.
— A, @Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 459,
pl. ceelxxxviii, figs. 9—13.
_ A. @Orbigny. Prodr. de Pal., vol. ii, p. 118.
— J. Morris. Cat. Brit. Foss., ed. 2, p. 196.
— F'. J. Pictet and H. Renevier. Foss. Terr. Aptien (Matér.
Pal. Suisse, ser. 1), p. 176.
— F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p- 36.
— I’. Stoliczka. Paleeont. Indica, Cret. Fauna 8. India,

vol. 1, p. 40.

~ G. Maas. Zeitschr. der deutsch. geol. Gesellsch., vol.

xlvii, p. 257.

L&vis, Maas. Ibid., p. 257.
srRiaAtuLA, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.

hollind. Neocoms (Abhandl. d. k.
preussisch. geol. Land., N. F., pt.
31), p. 144.

— A. Goldfuss. Petref. Germ., vol. 1,p.251, pl. ch, fig. 16
(C. substriatula, VOrbigny, 1850).

— J. Miller. Petref. der Aachen. Kreidet., pt. i, p. 25,

pl. u, fig. 8.

— A.d@Archiac. Bull. Soc. géol. de France, ser. 2, vol. xi,
p. 209, pl. iv, figs. 14, 15.

— J. Vilanova-y-Piera. Mem. geog.-agric. de Castellon,

pl. iii, fig. 14.
— O. Fraas. Aus dem Orient, p. 92.

— H. Credner. Zeitschr. der deutsch. geol. Gesellsch.,

vol. xxl, p. 236.

1 The type of Corbula punctum, Phillips, from Speeton, cannot be found, and I have not seen any
specimen which could be satisfactorily identified with that species. Phillips, ‘ Geol. Yorks.’ (1829),

p. 122, pl. ii, fig. 6.

CORBULA. 213

Non 1885. CorBoLaMEL£LA sTRIATULA, J. Bohm. Verhandl. d. nat. Vereines d. preuss.
Rheinl., vol. xlii, p. 144.

— 1887. — — F. Frech. Geitschr. d. deutsch. geol. Gesellsch.,
vol. xxxix, p. 173, pl. xii, figs. 5—8.
— 1888. — — G. Miller. Jahrb. d.k. preussisch. geol. Land.,

fiir 1887, p. 436.
-— 1889. Corsuxa srriatuna, O. Griepenkerl. Senon. vy. Konigslutter (Palont.
Abhandl., vol. iv), p. 69.

— 1897. — — A, Fritsch. Stud. im Gebiete der bohm. Kreide-
format., vi, Chlomek. Schicht., p. 64,
fie. 83.

— 1901. Corsunametua srrratuna, F. Sturm. Jahrb. d. k. preussisch. geol. Land.,
fiir 1900, vol. xxi, p. 88.

Description.—Shell ovate, usually much inflated, produced and _ pointed
posteriorly, inequilateral, slightly inequivalve. Anterior and ventral margins
rounded. Posterior margin short, obliquely truncated. Umbones broad, strongly
incurved, with a carina extending to the postero-ventral angle and cutting off
a flattened postero-dorsal area. Ornamentation consists of numerous concentric
ribs which extend on to the postero-dorsal area, where they are narrower and more

distinct.
Measurements :
(1) (2) (3)
Length ; 67 : 6:0 : 5°5 mm.
Height : 50 : 4:2 ; ArOn ee

(1) Atherfield Beds, East Shalford; (2, 3) Crackers, Atherfield.

Affinities—This species is distinguished from C. neocomiensis, d’Orbigny,' by
the smaller and more pointed posterior end. It differs from C. substriatula in being
less inequivalve and in possessing a distinct carina. Wollemann considers that
C. levis, Maas, is identical with C. striatula. Another form which appears to be
closely allied is C. neverisensis, de Loriol,? from the Gault of Cosne.

Remaris.—This species varies considerably in convexity and in relative length
and height. The shorter, more globose, and more distinctly rostrate forms agree
with the type. The more elongate and less convex forms are not so numerous,
and although differing considerably in shape from the globose forms, yet they
agree with them in other respects and do not appear to be specifically distinct.

Specimens from the Lower Greensand of Punfield resemble C. striatula, but
possess stronger concentric ribs—in some cases, as in the example figured (Plate
XXXIV, fig. 13), the ribs are considerably stronger, but in others the difference
is not so great.

1 «Pal. Franc. Terr. Crét.,’ vol. iii (1846), p. 457, pl. ecelxxxviii, figs. 3—5, and ‘ Prodr. de Pal.,’

vol. ii (1850), p. 76.
2 «Gault de Cosne’ (1882), p. 43, pl. v, figs. 23—25.

214 CRETACEOUS LAMELLIBRANCHIA.

Type.—Internal casts from the Hythe Beds of Pulborough, in the British
Museum.

Distribution.—Lower Greensand: Crackers of Atherfield. Recorded by Fitton
from the Perna-bed, Atherfield Clay, and Beds VI—IX, XIII, XIV near Atherfield.
Ferruginous Sands of Shanklin. Atherfield Beds of Peasmarsh, East Shalford
and Sevenoaks. Hythe Beds of Pulborough. Folkestone Beds of Folkestone.

CorBuLA GAULTINA, Pictet and Campiche, 1864. Plate XXXIV, figs. 14—16.

1864. CorpuLa cAauutina, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p- 34, pl. ¢, figs. 3, 4.
1870. —- — F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. iii, p. 40.

Description.—Shell subtriangular, rounded, inflated, shghtly mequivalve, a
little longer than high, moderately imequilateral. Anterior margin rounded.
Posterior margin subtruncate, oblique. Umbones prominent, rather high, curved
forward, with an inconspicuous carina cutting off a concave postero-dorsal area.
Ornamentation consists of small, concentric ribs.

Measurements :

(1) (2) (3) (4)
Length : oa 5:0 ; 4-6 , 4-0 mm.
Height : 50 : 405 : 40 ; 3°6

29
(1—4) Gault, Folkestone.

Affinities.—In this species the shell is relatively shorter and more inflated than
in C. elegantula, dOrbigny.’

C. gaultinw may perhaps be, as was pointed out by Pictet and Campiche,
identical with C. socialis, d’Orbigny,? of which no sufficient diagnosis has been
given.

Remarks.—Numerous individuals of this species are found close together in

groups. When the surface of the shell is not perfectly preserved the ribs become
indistinct.

From the Gault of Folkestone.
Distribution. Lower Gault (Bed 2) of Folkestone.

Type.

1 «Pal. Franc. Terr. Crét.,’ vol. iii (1846), p. 460, pl. eeclxxxviui, figs. 14—17.
2 «Prodr. de Pal.,’ vol. ii (1850), p. 136.

bo
—
Or

CORBULA.

CorBuLA TRUNCATA, Sowerby, 1836. Plate XXXIV, figs. 17—22.

1836. Corputa truncata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp. 240, 341, pl. xvi, fig. 8.

1850. — — A. d@Orbigny. Prodr. de Pal., vol. ii, p. 160.
1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 196.
1868. — = A. Briart and F. L. Cornet. Meule de Bracquegnies

(Mém. cour. et Mém. des Say. étrangers, vol. xxxiv),
p- 81, pl. vi, figs. 13—15.

1870. — _ F. Stoliczka. Paleont. Indica, Cret. Fauna 8S. India,
vol. ii, p. 40.
(?) 1895. — ef. — E. Tiessen. Zeitschr. d. deutsch. geol. Gesellsch.,

vol. xlvii, p. 485.

Non 1846. — — A. @Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 461,
pl. ceelxxxviii, figs. 18—20 (? C@.
Goldfussiana, Matheron).

Description.—Shell subquadrate or subtriangular, elongate, rounded, moderately
convex, inequilateral, shghtly imequivalve, considerably longer than high. Anterior
margin well rounded. Ventral margin slightly convex, its posterior part bending
upwards. Posterior margin obliquely truncated, forming an acute angle with the
ventral margin and an obtuse angle with the dorsal margin. Umbones broad,
with a carina extending to the postero-ventral angle and cutting off a flattened or
concave postero-dorsal area. Ornamentation consists of numerous fine, concentric
ribs which are continued on to the postero-dorsal area.

Measurements :

Q) (2) (3) (4)
Length . : s) 8°5 8 75 mm.
Height . ; ‘ 6°5 6 GW As DP

(1—4) Blackdown.

Affinities —This species is less elongate than C. trwicata, d’Orbigny, and is
also distinguished by its concentric ornamentation. It differs from OC. lineata,
Miller,’ in the greater obliquity of the posterior margin and in the more numerous
concentric ribs.

Type.—From Blackdown, in the Bristol Museum.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown.

1 Holzapfel, ‘Die Mollusk, Aachen. Kreide” (‘ Paleontographica,’ vol. xxxv, 1889), p. 146, pl. x,
figs. 16—19,

216 CRETACEOUS LAMELLIBRANCHIA.

Corsuta ELEGANS, Sowerby, 1827. Plate XXXIV, figs. 23—28.

1827. CorpuLa ELEGANS, J. de C. Sowerby. Min. Conch., vol. vi, p. 139, pl. dlxxii,

fig. 1.
1850. — = A. dOrbigny. Prodr. de Pal., vol. ii, p. 160.
1854. — = J. Morris. Cat. Brit. Foss., ed. 2, p. 195.
? 1867. — —— ?, B. Guéranger. Album Paldéont. de la Sarthe, p. 12,
pl. xvi, fig. 1.
1870. -- - F. Stoliczka. Palwont. Indica, Cret. Fauna 8. India,
vol. iu, p. 40.
Non 1846. — — A. ad Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 460,
pl. ceelxxxviu, figs. 14—17 (C. elegantula, VOrbigny,
1850).
? — 1847. - — ?, A. dArchiac. Mém. Soc. géol. de France, ser. 2,

vol. i, p. 302.

Description.—Shell subtrigonal, rounded, very convex, inequivalve, inequi-
lateral, a little longer than high.

Right valve with the anterior part sloping rapidly to the margin; anterior
margin rounded; ventral margin convex, its posterior part curving upwards.
Posterior part produced, compressed, separated from the sides by a groove passing
from the umbo to the postero-ventral angle; on the dorsal side of the groove is a
small carina. Posterior margin truncated, forming approximately a right angle
with the straight postero-dorsal margin. Umbo prominent, sharp, curved con-
siderably imward and somewhat forward. Ornamentation consists of strong,
broad, concentric ribs separated by narrow grooves, except on the postero-dorsal
area, Which is nearly smooth.

Left valve smaller, less convex, and with smaller ribs than the right valve.
Postero-dorsal area separated from the side of the valve by a groove or sharp

carina.
Measurements :
(1) (2) (3) (4)
Length . : : 6 Byey 5 4-5 mm.
Height. : ‘ 475 4rd 4. SOG ee

(1—4) Blackdown.

Affinities —This species is distinguished from C. elegantula, VOrbigny, by its
broader concentric ribs and rostrate posterior end. It is less globose, less pointed
posteriorly, and has stronger ribs than C. substriatula, @ Orbigny.

T'ype.—From Blackdown, in the British Museum.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown
and Haldon. Recorded by Price from the Upper and Lower Gault of
Folkestone.

Palxontographical Society, 1909.

Ae vO NO GR A Pa

OF THE

CRETACKOUS LAMELLIBRANCHIA
ENGLAND.

BY

HENRY WOODS, M.A.

UNIVERSITY LECTURER IN PALM OZOOLOGY, CAMBRIDGE,

VOL. I” PART Vi.

SOLENIDA, SAXICAVIDH, PHOLADIDA, TEREDINIDA, ANATINIDA,
PHOLADOMYIDA, PLEUROMYIDAH, POROMYACIDA, AND
CUSPIDARIID A.

Paces 217—260; Prares XXXV—XLIV.

LONDON:
PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY

1909.

PRINTED BY ADLARD AND SON, LONDON AND DORKING.

PHARUS.

bo
=
Sy

Fanvily—SOLENIDAS, Lamarck.

Genus—Puarus, Leach in J. EH. Gray, 1847.
(‘ Synops. Brit. Mus.,’ ed. 42, 1840, p. 154; ‘Ann. Mag. Nat. Hist.,’ vol. xx, 1847, p. 272 ;

and ‘ Proe. Zool. Soc.,’ 1847, p. 189.)
Puarus Warsurtont (Forbes), 1845. Plate XXXV, figs. 1—3.

1845. Sotecurrus Warsurtont, EL. Forbes. Quart. Journ. Geol. Soc., vol. 1,
p- 2387, pl. u, fig. 1.

1850. — _ A. @Orbigny. Prodr. de Pal., vol. ii, p. 117.
1854. — -- J. Morris. Cat. Brit. Foss., ed. 2, p. 224.
1864. — == F. J. Pictet and G. Campiche. Foss. Terr.

Crct. Ste. Croix (Matér. Pal.
Suisse, ser. 4), p. 30.
1879. — _ F. Stoliczka. Paleont. Indica, Cret. Fauna 8.
India, vol. ii, p. 99.

Description.—Shell elongate-oblong, compressed, slightly inequilateral, gaping
at the ends, the posterior higher than the anterior part. Dorsal margin
almost straight. Ventral margin slightly flexuous, and slightly oblique to the
dorsal margin. Anterior margin rounded. Posterior margin slightly truncate,
rounded. Umbones small, inconspicuous, sub-median. Ornamentation consists of
erowth-rings, and on the anterior part of the shell, of numerous, very small, rather
irregular, radial ribs.

Measurements :

(1) (2) (3) (4)
Length . 67 ; 60:5: 55 : 44. mm.
Height . 17 : 16 : 115) F PAS

(1—4) Crackers, Atherfield.

Affinities.—This species, as was pointed out by Stoliczka, closely resembles in
form living examples of the genus Pharus ; but the hinge appears to be unknown,
for although the species is well represented in collections, and the specimens are
in an excellent state of preservation, none of them shows the interior of the shell.
A single valve resembling P. Warburtoni, but relatively higher, has been described
by Dr. Kitchin! from the Uitenhage Series. Dr. Harbort? states that his So/ecurtus
longovatus is similar to our species, but is relatively higher and shorter.

1<« Ann. 8. African Mus.,’ vol. vii (1908), p. 155, fig. 1.

2 «Die Fauna d. Schaumburg-Lippe’schen Kreidemulde’ (1905), p. 71, pl. viii, fig. 6. An
imperfect internal cast found in the Upper Greensand of Devizes shows some resemblance to this

species.
9g

218 CRETACEOUS LAMELLIBRANCHIA.
T'ype.—From Atherfield, in the Museum of the Geological Society.

Distribution.—Lower Greensand (Crackers) of Atherfield. Atherfield Beds of
Kast Shalford and Sevenoaks. Sandgate Beds of Parham Park.

Genus—Sorecurtus, H. M. D. de Blainville, 1824.
(‘ Dict. Sci. nat.,’ vol. xxxii, p. 351.)

Sub-genus—Azor, W. LH. Leach, 1847.
(In Gray, ‘ Ann. Mag. Nat. Hist.,’ vol. xx, p. 272; and ‘ Proe. Zool. Soc.,’ 1847, p. 189.)

Sorecurtus (Azor?) Petaet, d@ Orbigny, 1850. Plate XXXV, fig. 4.

1850. Sontecurtus Pevaat, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 158.

1867. — — £. Guéranger. Album Paléont. de la Sarthe, p. 12,
pl. xv, fig. 6.
1870. — — F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,

vol. 11, p. 99.

Description.—Shell elongate, considerably inequilateral, moderately convex, but
slightly concave at the middle of the sides. Postero-dorsal area flattened or slightly
concave, limited by an indistinct carina. Antero-dorsal margin curved; anterior
margin rounded; postero-dorsal margin straight, nearly parallel to the ventral
margin; posterior margin curved, shghtly oblique. Ornamentation consists of
small concentric ribs near the umbo, and of growth-rings elsewhere. Length 30
mm.; height 12 mm.

Affinities —The identification of the English specimens with d’Orbigny’s species
is not quite free from doubt, since only two valves, both somewhat imperfect, have
yet been seen. In the specimen figured by Guéranger the postero-dorsal area
seems relatively higher than in our specimens; also the postero-dorsal margin is
less nearly straight, but this difference may be due to imperfect preservation.

S. Pelagi seems to be closely allied to S. Guerangeri, V@Orbigny,'’ but the
carina is less distinct, and the postero-ventral angle appears to be more rounded.

Until specimens showing the hinge satisfactorily have been found, the generic
position of this species must be regarded as doubtful.

T'ype.—From the Cenomanian of Le Mans.

Distribution —Upper Greensand (zone of Schlanbachia rostrata) of Blackdown.

1 «Pal. France. Terr. Crét.,’ vol. iii (1845), p. 321, pl. cecli, figs. 1, 2. Guéranger, ‘Album

Paléont. de la Sarthe’ (1867), p. 12, pl. xv, fig. 4. An internal cast of a left valve from the Upper
Greensand of Warminster resembles S. Guerangeri.

LEPTOSOLEN. 219

Sonecurtus? (Azor?) Acton, d’Orbigny, 1850. Plate XXXV, figs. 5, 6.

1850. Sorecurrus Acrzon, A. d’Orbigny. Prodr. de Pal., vol. 11, p. 158.

1867. — — £. Guéranger. Album Paléont. de la Sarthe, p. 12,
pl. xv, figs. 1, 2.
1870. — — F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,

vol. i, p. 99.

Description—Shell somewhat oblong, moderately imequilateral, moderately
convex, with flattened sides and flattened postero-dorsal area. Anterior margin
rounded ; postero-dorsal margin nearly straight, sloping ventrally from the umbo ;
posterior margin slightly convex, somewhat oblique ; ventral margin nearly parallel
to the dorsal margin and forming a rounded angle with the posterior margin.
Umbones broad, inconspicuous. Ornamentation consists of strong, regular, con-
centric ribs, separated by furrows of greater breadth.

Measurements (approvimate) :

(1) (2)
Length : ; 46 : 20 mm.
Height : 24. ; Os:

(1) Haldon, (2) Dunscombe.

Affinities —Only two specimens have been seen; they resemble closely
Guéranger’s figures of S. Acteon. The hinge is unknown, so that the generic
position cannot be determined at present.

Type.—From the Cenomanian of Le Mans.

Distribution—Upper Greensand (zone of Schlanbachia rostrata) of Haldon,
Cenomanian (Me¥er’s Bed 10) of Dunscombe, South Devon.'

Genus—Leproso.En, 7’. A. Conrad, 1867.
(‘Amer. Journ. Conch.,’ vol. iii, pp. 15, 188 ; F. B. Meek, ‘ Invert. Cret. and Tert. Foss.
U. Missouri,’ 1876, p. 252.)

a

LeprosoLen Duprntanus (d’Orbigny), 1845. Plate XXXV, figs. 7, 8.

1845. Soren Durrnranus, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ii, p. 320,
pl. eeel, figs. 3, 4.
1850. — — A. @Orbigny. Prodr. de Pal., vol. ii, p. 135.

1 An internal cast from the Cenomanian (Bed 11) of Dunscombe, South Devon, resembles
Solecurtus swqualis, V’Orbigny, but is not sufficiently well-preserved for identification. S. equalis has
been referred doubtfully to the genus Pharella by Stoliezka and by Meek, whilst de Loriol regards it
as belonging to Siliquaria (= Tagalus). See d’Orbigny, ‘ Pal. Frang. Terr. Crét.,’ vol. iii (1845),
p. 321, pl. ceel, figs. 5—7, and ‘Prodr. de Pal.,’ vol. ii (1850), p. 158; Gucranger, * Album
Paléont. de la Sarthe’ (1867), p. 12, pl. xv, fig. 3.

220 CRETACEOUS LAMELLIBRANCHIA.

1864. Soten pupryianus, F. J. Pictet and G. Campiche. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser. 4), p. 29.

1897. — _- R. B. Newton. Proce. Dorset Nat. Hist. and Antiq.
Field Club, vol. xviii, p. 93.

Description.—Shell elongate, more or less oblong, slightly convex, compressed
near the antero-dorsal margin, considerably inequilateral. Dorsal margin nearly
straight. Anterior end rounded, not so high as the posterior part of the shell.
Ventral margin nearly straight and nearly parallel to the dorsal margin, curving
upwards anteriorly. Posterior margin convex, forming a rounded angle with the
ventral margin. Umbones small, inconspicuous, situated at less than a third of
the length of the shell from the anterior margin.

Ornamentation consists of small concentric ridges; in some cases the ridges
cut the posterior part of the ventral margin obliquely. A strong internal rib
extends from the umbo ventrally, but does not reach the ventral margin.

Measurements :

(1) (2) (3)
Length ; ; 3} , 29 , 26 mim.
Height ; , 10 E 10 : Oma

(1—3) Gault, Black Ven.

Affinities —The occurrence of this species in the Gault of England has been
recorded by De Rance and R. B. Newton—by the former from Black Ven, and by
the latter from Okeford Fitzpaine. Although the example figured by d’Orbigny
is imperfect, consisting of the posterior part of a left valve only, yet the English
specimens agree sufficiently closely with d’Orbigny’s figure to make it probable
that they have been correctly identified with L. Dupinianus. In most of the
English examples, however, the posterior margin is more convex and the postero-
dorsal angle more rounded than in d’Orbigny’s figure; but in a few specimens,
which have been slightly crushed, these differences are not noticeable.

The species which resemble L. Dupinianus are L. concentristriatus (Miller'),
LL. Petersi (Reuss*), L. truncatula (Reuss*), L. Moreana (VOrbigny*) and L. limata
(Stoliczka’). .

T'ype.-—F rom the Albian of Ervy (Aube).

Distribution.—Lower Gault of Black Ven and Okeford Fitzpaine. Upper Green-
sand of Devizes. Recorded by Jukes-Browne from the Gault of the Isle of Wight.

1 «Jahrb. d. k. preussisch. geol. Landesanst. fiir 1887’ (1888), p. 431, pl. xvi, fig. 5.

2 “Kreideschicht. i. d. Ostalpen’ (1854), p. 145, pl. xxviii, fig. 10. Zittel, ‘Die Bivaly. d.
Gosaugeb.,’ I (1865), p. 5 [109], pl. i, fig. 3.

5 «Die Verstein. der bbhm. Kreideformat.,’ pt. 2 (1846), p. 17, pl. xxxvi. figs. 18, 16, 17.

4 «Pal. Franc. Terr. Crét.,’ vol. iii (1845), p. 324, pl. ecel, figs. 8—10. This species has been
recorded by Barrois from the Upper Greensand of Lulworth and Devizes; I have not seen any
examples from those localities.

5 «Paleont. Indica, Cret. Fauna 8. India’ (1870), p. 101, pl. i, figs. 12, 13.

PANOPEA. 221

Family—SAXICAVIDA, Gray.

Genus—Panorea, Ménard de la Groye, 1807.
(‘ Ann. Mus. Hist. nat., Paris,’ vol. ix, p. 151, pl. xi.)

Panopna, sp. Text-fig. 27.

Internal casts of a large, convex Panopea occur in the Tealby Limestone of

Fig. 27.—Panopea, sp. ‘Tealby Limestone, North Willingham, Lincolnshire. Sedgwick Museum, Cambridge. x {,

Hainton, Claxby, and North Willingham, Lincolnshire. In form they resemble
some varieties of P. gurgitis, but the posterior part of the shell is more elongated.
One specimen shows a large external ligament, and on a small portion of shell
indications of radial rows of fine granules are seen. The pallial sinus is large and
rounded.

222 CRETACEOUS LAMELLIBRANCHIA.

PANOPEA SPILSBIENSIS, sp. nov. Plate XXXVIII, fig. 2a, b.

Description.—Shell elongate-oval, convex, not very inequilateral. Posterior
part more compressed and not so high as the median and anterior parts. Anterior
margin rounded; ventral margin slightly curved, not quite parallel to the long
dorsal margin. Umbones broad, incurved, at about six-fifteenths of the entire
length from the anterior end. Pallial sinus large, deep, and rounded. Surface of
shell nearly smooth.

Remarks.—Only a few internal casts with small portions of the shell preserved
have been obtained, but they seem to differ considerably from other species and
are provisionally referred to the genus Panopea.

Distribution.—Spilsby Sandstone (zone of Belemnites lateralis) of Donnington.

PANoPEA -GuRGITIS (Brongniart), 1822. Plate XXXV, figs. 9—14; Plate XXXVI,
figs. 1—8.

1822. Lurrarra eurerris, A. Brongniart,in Cuvier. Ossemens Foss., vol. ii, pt. 2,

pp. 333, 615, pl. ix, fig. 15.

1825. Mya pricara, J. de C. Sowerby. Min. Conch., vol. v, p. 20, pl. eccexix, fig. 3.
1835. Panopma pricara, Sowerby. Ibid., vol. vi, Systemat. Index, p. 241.
1841. — _ F. A. Romer. Die Verstein. d. nord - deutsch.

Kreidegeb., p. 75, pl. ix, fig. 25.
1842. PHoLtapomya NnEocomrensis, A. Leymerie. Mém. Soc. géol. de France, ser. 2,
vol. v, p. 3, pl. iu, fig. 4.
— Prevostr, Deshayes in Leymerie. Ibid., p. 3, pl. i, fig. 7.
1845. Panopma neocomrensis, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii,
p- 329, pl. cecliii, figs. 3—8.
- Prevosti, d’Orbigny. Ibid., p. 334, pl. ceclvi, figs. 3, 4.
nEocomigEnsIs, 2. Forbes. Quart. Journ. Geol. Soe., vol. i, p. 238.
= puicata, Forbes. Lbid., p. 238.
— Myopsis ngocomiensis, L. Agassiz. Etudes crit. Moll. Foss., Myes, p. 257,
pl. xxxi, figs. 5—10.
= — UNIOIDES, Agassiz. Ibid., p. 258, pl. xxxi, figs. 11, 12.
1850. Panopma NeEocomigEnsIs, A. d’Orbigny. Prodr. de Pal., vol. ii, pp. 73, 117.
= - Prevosrit, dOrbigny. Ibid., pp. 105, Maley
1852. - piicata, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de
Gentve, p. 399, pl. xxvii, fig. 2.
— — Ruopant, Pictet and Roux. Ibid., p. 400, pl. xxviii, fig. 3.
1854. Myacrres neocomiensis, J. Morris. Cat. Brit. Foss., ed. 2, p. 218.
1855. Panopma — F. J. Pictet and E. Renevier. Foss. Terr. Aptien
(Matér. Pal. Suisse, ser. 1), pp. 56, 175, pl. vi,
figs. 2, 3.

-= — piicata, Pictet and Renevier. Ibid., p. 57, pl. vi, figs. 4, 5.

1855.
1861.

1864-5.

1898.

1900.

1905.

1906.

1908.

Non 1827.

— 1837.

PaNopma

PANOPEA.

bo
bo
os)

NEocomtENsIs, G. Cotteaw. Moll. Foss. de ’Yonne, p. 51.
— P. de Loriol. Anim. Invert. Foss. Mt. Saltve,
p- 59.
— EF. J. Pictet and G. Campiche. Foss. Terr. Crcét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p- 49, pl. ¢, figs. 1O—12.
piicata, Pictet and Campiche. Ibid., p. 63.
NEOCOMIENSIS, P. de Loriol and V. Gilli¢ron. Urgon. infér. de
Landeron, p. 10, pl. i, fig. 10.
— F. Stoliezka. Paleeont. Indica, Cret. Fauna 8.
India, vol. in, p. 87.
puncraTo-piicata, G. Bihm. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxix, p. 241.
pLicata, W. Keeping. Foss., ete., Neoc. Upware and Brickhill,
p. 126.
NEOCOMIENSIS, O. Weerth. Die Fauna des Neocom. im Teutoburg.
Walde (Paleont. Abhandl., vol. 11),
p. 37, pl. viii, fig. 7.

PLEUROMYA — H. Trautschold. Néocom. de Sably (Nouy. Mén.

PanoPpma

Soc. Impér. Nat. Moscou, vol. xv), p. 135.
— O. Behrendsen. Zeitschr.d. deutsch. geol. Gesellsch.,
vol. xliv, p. 20.
G. Maas. Ibid., vol. xlvii, p. 256.
= F. Vogel. Hollindisch. Kreide, p. 59.
_- A.Wollemann. Zeitschr.d. deutsch. geol. Gesellsch.,
vol. xlviii, p. 849.

Prevromya puicata, R. B. Newton. Proc. Dorset Nat. Hist. and Antiq.

PANOPMA

Field Club, vol. xviii, pp. 71, 93,
pl. u1, figs. 4, 5.
NnEocomigEnsis, E. G. Skeat and V. Madsen. Jur. Neoc. and
Gault Boulders in Denmark (Danmarks geol.
Undersig., 2 R., Nr. 8), p. 185, pl. vi, fig. 11.
— A. Wollemann. Die Biv. u. Gastrop. d. deutsch.
u. holliind. Neocoms (Abhandl. d. k.
preussisch. geol. Land., N. F., pt. 31),
p. 124.
= E. Harbort. Die Fauna d. Schaumburg-Lippe-
’schen Kreidemulde (ibid., pt.
45), p. 74.
— A, Wollemann. Jahrb. d. k. preuss. geol.
Landesanst. fiir 1906, vol.
xxvii, p. 278.
— A. Stojanoff. Ann. géol. et min. de la Russie,
vol. x, p. 115.

Lurrarta Gurertis, S. Nilsson. Petrif. Suecana, p. 18, pl. v, fig. 9 (Glyei-

meris Holzapfeli, Hennig).
— W. Hisinger. Lethwa Suecica, p. 67, pl. xx, fig. 1.

224 CRETACEOUS LAMELLIBRANCHIA.

Non 1840. Panopma Gurerres, A. Goldfuss. Petref. Germ., vol. ii, p. 274, pl. cliii,
fig. 7 (P. Goldfussi, A Orbigny,

1850).
—- — — piicaTa, Goldfuss. Ibid., p. 274, pl. elviii, fig. 5.
1845. — curaitis, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 345,
pl. ecelxi, figs. 1, 2.
— 1846. ~- —- A. BH. Reuss. Die Verstein. der bohm. Kreideformat.,
pt. 2, p. 17, pl. xxxvi, fig. 3.
— 1847. —_ piicata, J. Miller. Petref. der Aachen. Kreidef., pt. 1, p. 28
(Glycimeris Geinitzi, Holzapfel).
ss 1si78t = curaitis, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto-

graphica, vol. xx, pt. 2), p. 68, pl. xix,
figs. 1, 2.
— 1876. - -- D. Brauns. Zeitschr. f. d. gesammt. Naturwiss., vol.
xlvi, p. 362.
— 1877. — — A. Fritsch. Stud. im Gebiete der bohm. Kreideformat.,
iil, Weissenberg. u. Malnitz. Schichten,
p- 125, fig. 100.
— 1898. GuycIMERIS — G. Miller. Die Mollusk. d. Untersenon y. Braun-
schweig u. Ilsede, p. 70, pl. x, fig. 4.
— 1901. Panop®a — F. Sturm. Jahrb. d. k. preuss geol. Landesanst. fiir
1900, vol. xxi, p. 70, pl. x, fig. 4

Description—Shell more or less oblong, rounded, convex; posterior part
somewhat compressed, anterior part sloping more or less rapidly to the margin ;
moderately or considerably inequilateral; posterior gape large. Anterior margin
more or less convex, sometimes subtruncate; antero-ventral margin rounded ;
ventral margin slightly or moderately convex, nearly parallel to the dorsal margin ;
posterior margin convex, or subtruncate and rounded; postero-dorsal margin
nearly straight. _Umbones incurved, often broad, sometimes narrow and pointed ;
the dorsal part of the shell in front of the umbones is moderately or considerably
depressed; sometimes a more or less distinct carina extends from the umbo
towards the antero-ventral extremity; another carina, usually faint, may extend
from the umbo posteriorly. Pallial sinus large, rounded.

Ornamentation consists of concentric folds, which may be conspicuous or only
faintly indicated, and of numerous radial rows of minute granules.

Measurements :

(1) (2) (3) (4) (5) (6) (7) (8) (9)
Length . -93 = 80 . 7695-6" i) 1617 oom wo ner. 3) 4 oy) isaiea,
Height . 49 .. 46... 36 = ~38 (do) 290s s 29d ees

(1,5) Perna-bed, Atherfield.
(3, 4, 6—9) Crackers, Atherfield.
(2) Ferruginous Sands, Shanklin.
Affinities.—This species has been referred by most authors to the genus

PANOPEA. 225

Panopea, but by some to Plewromya.! There seems now to be sufficient evidence
to show that it belongs to the former rather than the latter, since the hinge-margins
of the two valves are alike and there is no overlap of left by the right margin;
the hinge possesses the prominent, conical tooth characteristic of Panopea (Plate
XXXVI, fig. 6); and a well-developed, broad, external ligament is present (Plate
XXXV, figs.9b, 116). The fine radial ornamentation (Plate XXXV, fies. 9c, 13D)
agrees perfectly with that found in Tertiary species of Panopea.? I have not seen
the hinge in any specimen from the Lower Greensand, but it is well preserved in
a left valve from Blackdown. Pictet and Campiche’ state that casts from the Aptian
show clearly the presence of the teeth of Panopea.

Pictet and Renevier thought that P. plicata (Sowerby) and P. neocomiensis
(Leymerie) should be united as one species; Pictet and Campiche, however, in a
later work regarded them as distinct, and stated that the former differs from the
latter by the possession of strong concentric folds and by the absence of fine radial
ornamentation. But when numerous specimens are examined all stages in the
strength of the folds can be seen; and those with well-developed folds show, when
the surface is well-preserved, the same kind of radial ornamentation that occurs on
specimens with indistinct folds. The presence of a carina in front of the umbones
and the somewhat smaller height of the posterior part of the shell have also been
mentioned as characteristic of P. neocomiensis, but these features are now known
to be inconstant. It appears, therefore, that there is no character by which P.
plicata can be separated from P. neocomiensis.

It is evident from Brongniart’s remarks that his specimens of Lutraria gurgitis
came from the Perte-du-Rhéne. Pictet and Renevier,t who had seen the type of
that species in the collection of M. Deluc, recognised it as a specimen from the
Aptian of the Perte-du-Rhoéne, and state that it is certainly an example of either
P. neocomiensis or P. plicata. Since these two forms are now united it follows
that the earlier name given by Brongniart should be used for this species. Later
writers have unfortunately used the name gurgitis for a species from the Chalk.

P. acutisuleata (Deshayes’) and P. Schréderi (Wollemann’) appear to be closely
allied to P. quigitis.

1 For an account of the characters of this genus see Terquem, ‘ Bull. Soc. géol. de France,’ ser. 3,
vol. x (1853), p. 534, and “ Observations sur les Etudes critiques des Mollusques Fossiles comprenant
la monographie des Myaires de M. Agassiz,” ‘ Mém. Acad. Imp. de Metz,’ année 1854—55 (1855), p, 253.

2 See, for instance, P. intermedia (Sow.) from the London Clay, ete., and P. floridana, Heilprin,

from the Caloosahatchie Beds of Florida. 3 «Terr. Cret. Ste. Croix’ (1865), p. 51.

4 «Foss. Terr. Aptien’ (* Matér. Pal. Suisse,’ ser. 1, 1855), pp. 56 (footnote), 175.

5 Leymerie, ‘Mém. Soc. géol. de France,’ ser. 2, vol. v (1842), p. 3, pl. ii, fig. 2; d’Orbigny,
‘Pal. France. Terr. Crét.,’ vol. iii (1845), p. 336, pl. ecelvii, figs. 1—3,; Pictet and Campiche, ‘Terr.
Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser. 4, 1865), p. 65.

6 «Die Biv. u. Gastrop. d. deutsch. u. holliind. Neocoms’ (‘Abhandl. d. k. preussisch. geol. Land.,

N. F., pt. 31, 1900), p. 126, pl. v, fig. 7.

226 CRETACEOUS LAMELLIBRANCHIA.

P. leviuscula (Sowerby'), from the Upper Greensand of Blackdown, closely
resembles the small forms of the neocomiensis variety of P. gurgitis and does not
appear to be specifically distinct. The type consists of an imperfect right valve ;
a specimen similar to the type, but with both valves preserved, is in the Museum
of Practical Geology (No. 23,823).

Remarks.—Previous writers have remarked on the great amount of variation
shown by this species. At first sight some of the varieties appear to be distinct,
but, as Wollemann has pointed out, when a large number of specimens are
studied, transitions can be traced between the different forms. The varieties do
not appear to be confined to definite horizons, and nearly all of them are found
together in the Perna-bed and Crackers of Atherfield.

Considerable differences are seen in the position of the umbones, so that some
specimens are much more inequilateral than others ; in those in which the anterior
part is relatively short the anterior slope is rapid. The size and depth of the
depression in the lunular region show considerable variation; when large and
deep the umbones are usually narrower and more pointed than when the depression
is small and shallow, and in the former case the carina extending from the umbo
to the antero-ventral margin is usually distinct. The relative length and height
of the shell, the rounded or truncate character of the anterior margin, the
curvature of the ventral margin, the height of the posterior end, and the convexity
of the anterior compared with that of the posterior part of the shell also show
more or less considerable differences. The concentric folds may be conspicuous,
but are sometimes indistinct; sometimes they appear to be better marked on
internal casts than on the shell itself; in some cases their prominence is due to the
state of preservation of the shell; thus Wollemann mentions a specimen in
which one valve is weathered and shows strong folds, whilst the other valve is
well preserved and nearly smooth.

Some forms of this species are represented by a larger number of individuals
than others. One common form (Plate XXXVI, figs. 3, 4), agrees more or less
closely with the type of P. plicata (Sowerby), and it may perhaps be convenient
to refer to this as P. gurgitis var. plicata. In this the concentric folds are usually
prominent, the ventral margin is only slightly curved, the posterior part of the
shell is of nearly the same height as the anterior part, and the lunular depression
is distinct and usually large.

Another form (Plate XXXV, figs. 9, 13) resembles P. neocomiensis (Leymerie)
and may be referred to as P. gurgitis var. neocomiensis. The concentric folds are

1 Mya leviuscula, J. de C. Sowerby, ‘Trans. Geol. Soe.,’ ser. 2 (1836), vol. iv, pp. 241, 340,
pl. xvi, fig. 6; Morris, ‘ Cat. Brit. Foss.,’ ed. 2 (1854), p.212. Panopea leviuscula, @’ Orbigny, ‘ Prodr.
de Pal.,’ vol. ii (1850), p. 157; Pictet and Campiche, ‘Terr. Crét. Ste. Croix’ (‘Matér. Pal. Suisse,’
ser. 4, 1865), p. 70.

PANOPEA. 227

usually less distinct than in the variety plicata, the lunular depression is smaller
and shallower, the umbones broader, and the ventral margin usually more distinetly
curved. The smaller specimens of the var. neocomiensis resemble the example
figured by d’Orbigny, in which the anterior margin is obliquely truncated, and
a carina extends from the umbo antero-ventrally.

In one form (Plate XXXV, fig. 10), which in other respects resembles the
variety neocomiensis, the anterior half of the shell is relatively more inflated, and
the posterior part is not so high as the anterior part; this form may be known
as P. gurgifis var.a. In addition to these forms of P. gurgitis numerous other
modifications occur.

Specimens from the Speeton Clay have been recorded by previous writers as
P. neocomiensis; the examples seen are few in number and not well preserved,
but resemble closely the smaller form of P. gurgitis var. neocomiensis (Plate XXXV,
fig. 13). In one case the fine, radial ornamentation is shown.

Specimens from Blackdown (Plate XXXVI, figs. 6, 7) resemble the variety
plicata from the Lower Greensand, but are somewhat less convex ; these probably
constitute only a local variety, since examples from the Upper Greensand of Dorset
agree in convexity and in other characters with typical forms of the var. plicata
from the Lower Greensand. The examples from Blackdown, although few in
number, show considerable variation; one specimen (Plate XXXVI, fig. 8), is
much shorter than usual, and resembles d’Orbigny’s' figure of P. plicata, but
is less convex.

Crushed internal casts of Panopea have been found in the Chalk Marl of
Folkestone ; they resemble P. gurgitis var. plicata, but their imperfect preservation
renders determination difficult.

T'ypes.—The type of P. gurgitis came from the Aptian of the Perte-du-Rhone ;
that of P. neocomiensis from the Neocomian of Aube. The type of P. plicata
was obtained from the Lower Greensand of Sandgate, but cannot now be found.
The type of P. leviuscula, from the Upper Greensand of Blackdown, is in the
Bristol Museum.

Distribution.— Lower Greensand : Perna-bed, Crackers and Beds iv, vi, vii, x,
xiii, and xiv of Atherfield. Perna-bed of Sandown. Ferruginous Sands of Shanklin.
Atherfield Beds of East Shalford and Sevenoaks. Hythe Beds of Hythe and
Court-at-Street. Sandgate Beds of Parham Park. Mamimillatus Bed of Folke-
stone. Recorded by Topley from the Atherfield Clay of Haslemere, Peasmarsh,
Redhill, and Hythe; from the Hythe Beds of Pulborough; from the Sandgate
Beds of Folkestone and Sandgate; and from the Folkestone Beds of Folkestone.
? Lower Greensand of Upware. ?Speeton Clay of Speeton. Gault of Black Ven
and Folkestone. Upper Greensand of Blackdown and Black Ven.

1 «Pal. France. Terr. Crct.,’ vol. iii (1845), p. 337, pl. ecelvii, figs. 4, 5.

228 CRETACEOUS LAMELLIBRANCHIA.

PANOPEA MANDIBULA (Sowerby), 1813. Plate XX XVII, figs. 1—5.

1813. Mya manpipura, J. Sowerby. Min. Conch., vol. i, p. 93, pl. xliii.
r 1840. Panopwa Baumonti, A. Goldfuss. Petref. Germ., vol. 1, p. 274, pl. clviii,

fig. 4.
? 1841. -- Jueuert, F. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p- 79, pl. x, fig. 4.
1845. — MANDIBULA, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 344,
pl. eeelx, figs. 3, 4.
1850. — — H. B. Geinitz. Das Quadersandst. oder Kreidegeb.

in Deutschland, p. 146.
1854. Myacrres manpisuta, J. Morris. Cat. Brit. Foss., ed. 2, p. 213.

1865. Panopma -- F. J. Pictet and G. Campiche. Terr. Crét. Ste. Croix

(Matér. Pal. Suisse, ser. 4), p. 70.

1870. = == F. Stoliczka. Palzeont. Indica, Cret. Fauna 8. India,
vol. 1, p. 87.

1873. — a H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal-

eontographica, vol. xx, pt. 2), p.
70, pl. xviii, figs. 20, 21.

? 1883. — — A. Fritsch. Stud. im Gebiete der bihm. Kreide-
format., ii, Iserschicht., p. 108.
? 1897. — = Fritsch. Ibid., vi, Chlomek. Schicht., p. 60.
1900. PLevromMya — A.J. Jukes-Browne. Cret. Rocks of Britain, vol. i,
p- 470.

Description. — Shell oblong or rhomboidal in outline, very inequilateral,
convex, anterior part sloping rapidly to the anterior margin, with a wide posterior
gape. Anterior margin somewhat convex; antero-ventral extremity rounded;
ventral margin straight or slightly curved and nearly parallel to the dorsal
margin; postero-ventral extremity rounded; posterior margin truncated, nearly
straight, either perpendicular or slightly oblique to the nearly straight postero-
dorsal margin. Umbones prominent, narrow, pointed, considerably incurved,
with a broad, shallow furrow extending from their posterior side to the postero-
ventral part of the valves. In front of the umbones the shell is considerably
depressed.

Ornamentation consists of strong, rounded, concentric folds, which become
less distinct in and posterior to the dorso-ventral furrow; and of radial rows of
minute granules.

Measurements :

(1) (2) (3) (4) (5) (6)
Length «= 72+. ° 70° « 53. Sa 49-2 eoaum
Beight . of ~ 46 = Ale S8Q28o 08:
Thickness. 41 39 _- 28 2G «2, “2h 5

(1, 4—6) Upper Greensand, Ventnor.
(2, 3) Upper Greensand, Devizes.

PANOPEA. 229

Affinities. —The more elongate forms of this species resemble some specimens
of P. gurgitis var. plicata, but are more inequilateral, more convex, usually
relatively longer, with narrower and more pointed umbones, and with a distinct
furrow extending from the umbo to the postero-ventral margin.

Remarks.

Many of the specimens are more or less crushed, and nearly all are
internal casts, but the shell is preserved in some specimens from the Gault, and
shows radial rows of fine granules. The hinge is not seen in any instance.
P. mandibula is common in the Upper Greensand of Ventnor and Devizes, and is
less abundant at other horizons. The principal variation seen is in the relative
length and height of the shell.

T'ype—From the Upper Greensand of Devizes, in the British Museum.

Distribution.—Lower Greensand of Atherfield. Atherfield Beds of Sevenoaks.
Sandgate Beds of Nutfield. Folkestone Beds of Folkestone. Upper Greensand
(zone of Schlanbachia rostrata) of Devizes and Ventnor. Gault and Upper
Greensand of Black Ven. Chalk Marl of Folkestone.

PANOPEA OVALIS, Sowerby, 1836. Plate XXXVII, fig. 6a, b.

1836. Panopxa ovatts, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp.
241, 340, pl. xvi, fig. 5.

1850. = — A.d'Orbigny. Prodr. de Pal., vol. ii, p. 157.

1854. Myactres — J. Morris. Cat. Brit. Foss., ed. 2, p. 214.

Description—Shell oval, convex, moderately imequilateral. Antero-dorsal
margin slightly convex; anterior margin rounded, passing gradually into the
slightly convex ventral margin. Umbones broad, incuryed. The parts of the
shell in the front of and behind the umbones are considerably depressed. ‘The
surface is ornamented with growth-rings.

Remarks.—The only specimen seen is the type, in which the posterior part of
the shell is not preserved.

Type.—In the British Museum.

Distribution Upper Greensand (zone of Schlanbachia rostrata) of Blackdown.

Panopea Meyert, sp. nov. Plate XXXVIII, fig. 1a, b.

Description —Shell oval, moderately convex, with flattened sides, slightly
inequilateral, with a wide posterior gape. Antero-dorsal margin convex. Anterior

230 CRETACEOUS LAMELLIBRANCHIA.

margin rounded. Ventral margin straight or slightly convex. Posterior margin
truncated, slightly convex. Postero-dorsal margin slightly concave, nearly parallel
to the ventral margin. Umbones broad, curved inwards and backwards. The
part of the shell in front of the umbones is slightly depressed; the part behind the
umbones is more deeply depressed. Surface with well-marked growth-rings.
Length 87 mm.; height 59 mm.

Afjinities.—In this species the sides of the shell are more flattened, the antero-
dorsal margin is more convex, and the part of the shell in front of the umbones is
less depressed than in P. ovalis. he hinge has not been seen, but the form of the
shell agrees closely with that of typical species of Panopea.

Fic. 28.—Panopea, sp. Lower Greensand (“ Seaphites” Beds), Whale Chine, Atherfield. Sedgwick
Museum. Internal cast of right valve. Natural size.
Remarks.—In addition to the specimen figured, which was collected by
C. J. A. Mejer, an internal cast and the posterior part of a left valve only have
been seen.
Distribution.—Upper Greensand (zone of Schlenbachia varians) of Blackdown.

Panorga, sp. ‘Text-fig. 28.

Internal casts resembling 2. Meyert, but with the posterior border obliquely
truncated, occur in the Lower Greensand (“Scaphites” Beds) of Whale Chine,
Atherfield.

MARTESIA. 231

Family—PHOLADID.A, Leach.

Genus—Marvresta, Leach in H. M. D. de Blainville, 1825.
(‘ Manuel de Malacol.,’ p. 632.)

Marresta consrricta (Phillips), 1829. Plate XXXVIII, figs. 3—10.
1829. PuHoxas consrricra, J. Phillips. Geol. Yorks., p. 169 (p. 256, ed. 3), pl. u,

fig. 17.
1850. = = A. @Orbigny. Prodr. de Pal., vol, ii, p. 117.
1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 221.
1864. — — F. J. Pictet and G. Campiche. Foss. Terr. Crct. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p. 26.
1870. = = F. Stoliczka. Paleont. Indiea, Cret. Fauna 8. India,

p. 23 (? Martesia).
1900. PuHoxtapipEa consrricta, A. J. Jukes-Browne. Cret. Rocks of Britain,
vol. i, p. 470.

Deseription.—Shell small, more or less elongate; anterior part short, convex,
rounded; posterior part wedge-shaped. Umbones prominent, close together,
curved inwards and forwards. Ventral margin nearly straight. Posterior margin
sub-truncate, more or less rounded, somewhat oblique. Postero-dorsal margin
sloping ventrally. Two narrow furrows, with corresponding internal ribs, extend
from the umbo to the ventral margin; the anterior furrow is rather broader and
less oblique than the posterior, but is sometimes short or absent. An internal
ridge, near the postero-dorsal margin, extends from the umbo to near the posterior
adductor. Anterior callus shield-shaped. Ventral margin of valves diverging
posteriorly, jomed by a hypoplax. Metaplax elongated, divided.

Ornamentation: on the larger part of the shell distinct, regular, concentric
ribs with minute transverse serrations. In front of the anterior furrow the ribs
become smaller and closer together; they bend dorsally and unite at an angle
with similar ribs on the dorsal part of the anterior end of the valve. On the
postero-dorsal part of the shell the ribs are less regular and less distinct.

Measurements :

(1) (2) (3) (4) (5) (6) (7)
Rites. te. 86 7 Is... 1b. 14 » 10 mm.
Moswmeeere tee 19 OO. AD. Os Fs GO ,
Thickness CO ee Om em hOr tr Oh.) 7205, - Gro’,

(1—3) Speeton, (4—7) Folkestone.
Affinities—This species is less elongate than M. subeylindrica (d’Orbigny)..
1 «Pal. France. Terr. Crét.,’ vol. iii (1845), p. 306, pl. ecexlix, figs. 5—8.

232 CRETACEOUS LAMELLIBRANCHIA.

The height of the anterior part of the shell is less and the length of the ventral
margin greater relatively than in M. Sancte-Crucis (Pictet and Campiche).!

Remarks.—This species varies somewhat in relative length and breadth, and
in the extent of the development of the anterior furrow. Many of the specimens
are found in burrows in wood. The protoplax is not preserved in any example seen.

T'ype.—The type came from Speeton, but cannot now be found.

Distribution—Speeton Clay of Speeton. Lower and Upper Gault of Folkestone.
Probably also in the Upper Greensand of Blackdown. Specimens which belong to
either this or a closely allied species occur in the Spilsby Sandstone of Benniworth
Haven. Borings in wood found in the Tealby Limestone of Claxby may be due
to this species but the valves are concealed.

Marresia prisca (Sowerby), 1828. Plate XX XVIII, fig. 11.

1828. PuHoxas priscus, J. de C. Sowerby. Min. Conch., vol. vi, p. 157, pl. dixxxi.
1845. PHonas? priscus, H. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 237.
1850. Puonas prisca, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 72.

1854. -- — J. Morris. Cat. Brit. Foss., ed. 2, p. 221.

1864. = — FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser. 4), p. 26.

1870. — — (Marvesia), F. Stoliczka. Paleont. Indica, Cret. Fauna

8. India, vol. ii, p. 22.
1875. PuHonaprpxa Prisca, R. Ltheridge in W. Topley. Geol. Weald, p. 419.

This species appears to be closely related to M. coustricta, but no satisfactory
description can be given until better specimens have been obtained. The type, in
which the shell was well preserved, cannot now be traced; in other examples the
shell is concealed by a coating of hard matrix, and in the few cases in which it has
been possible to remove the matrix only internal casts of the valves have been
exposed. The type came from the Lower Greensand (? Sandgate Beds) near
Sandgate. Other specimens have been obtained from the Hythe Beds of Hythe
and Maidstone.”

1 «Foss. Terr. Crét. Ste. Croix’ (1864), p. 24, pl. e, fig. 1. This species has been recorded by
Price from the Gault of Folkestone; I have not seen any examples of it.

> Fistulana pyriformis, Mantell, is perhaps a Martesia, but no specimens showing the valves have
been seen. No figure or specific description was given by Mantell. The “type”? came from
Willingdon near Eastbourne, apparently from the top of the Lower Greensand. Mantell, ‘ Foss. 8.
Downs’ (1822), p. 76; Gastrocheena pyriformis, Morris, ‘Cat. Brit. Foss.,’ ed. 2 (1854), p. 203 ;
Pictet and Campiche, ‘ Foss. Terr. Crét. Ste. Croix (Matdér. Pal. Suisse,’ ser. 4, 1864), p. 18 ; Stoliezka,
‘Paleont. Indica, Cret. Fauna 8S. India,’ vol. iii (1870), p. 29.

Gastrochena dilatata, Deshayes, has been recorded by Forbes and other writers from the Lower
Greensand; I have not seen any specimens in which the valves are exposed. Deshayes, in Leymerie,
‘Mém. Soe. géol. de France,’ vol. v (1842), p. 2, pl. iii, fig. 1; Forbes, ‘ Quart. Journ. Geol. Soc.,’ vol. 1
(1845), p. 237; Pictet and Campiche, ‘ Foss. Terr. Crét. Ste. Croix’ (1864), p. 11, pl. xcix, figs. 4, 5.

TURNUS. 233

Marvesta ? rorunDA (Sowerby), 1850. Plate XXXVIII, figs. 12 a—e, 13.

1850. Terepo rorunpus, J. de C. Sowerby in F. Dixon. Geol. Sussex, p. 346 (p.
382, ed. 2), pl. xxviii, figs. 27, 28.

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 227.

1897. Marresta? rorunpa, H. Woods. Quart. Journ. Geol. Soc., vol. liii,

p- 393, pl. xxviii, figs. 15—18.

Description.—Shell small, ovoid, inflated, with rounded outline. Anterior gape
large, apparently closed by callus. Umbones sub-median, curved inwards and
forwards. A strong groove and a corresponding internal rib pass from the umbo
to the ventral margin. Near the dorsal margin a strong, narrow internal rib passes
backward from the umbo but does not reach the posterior margin. Ornamentation
posterior to the groove consists of concentric ribs and of two radial ribs imme-
diately behind the groove ; anterior to the groove are a few regular radial ribs, and
concentric ribs parallel to the margin of the anterior gape. Length, 7 mm.;
height, 5°5 mm.; thickness, 5 mm.

Remarks.—I have seen only three casts of the interior and two of part of the
exterior of this species, so that at present it is difficult to determine satisfactorily
its generic position.

T'ype.—The type came from the Chalk of Kent, but cannot now be found.

Distribution.—Chalk Rock of Cuckhamsley (Berkshire), and of Whyteleafe
(Surrey).

Genus—Turnus, W. M. Gabb, 1864.

(‘ Geol. Sury. California,’ Paleontology, vol. i, p. 145.)

Turnus Dattasi (Walker), 1866. Plate XXXVIII, figs. 14 a, b, 15.

oS

1866. PxHoxas Datuast, J. F. Walker. Ann. Mag. Nat. Hist., ser. 3, vol. xviii,

p. 386, pl. xiii, figs. 3, 4.

Description.—Shell ovate, short, inflated in front, wedge-like behind. Margin
of the anterior gape oblique, gently curved. Posterior margin rounded. Umbones
prominent, curved inwards and forwards. A narrow furrow, and a corresponding
internal rib, extend from the umbo to the ventral margin in a somewhat oblique
direction, and the furrow is crossed by small ribs. A broad and strong internal rib

3H

23.4 CRETACEOUS LAMELLIBRANCHIA.

passes from the umbo to near the postero-ventral margin. The shell is ornamented
with small concentric ribs, which bend dorsally in front of the furrow and become
parallel to the anterior margin.

Measurements :

(1) (2)
Length : : A 15 : S mm.
Height 5 é : 11 , Oi eee
Thickness , ; : —- ; 65

Affinities —The very slight curvature of the anterior margin and of the anterior
ribs distinguishes this species from the one described below.

Remarks.—T’. Dallasi occurs commonly boring in wood.

Type.—From Potton; in the Sedgwick Museum.

Distribution.—Lower Greensand of Potton.

Turnus, sp. Plate XXXVIII, figs. 16, 17.

Description—Shell oval, inflated, posterior end wedge-like. Ventral margin
curved ; posterior marginrounded. Antero-ventral excavation angular. Umbones
prominent, anterior, incurved, close together. An external furrow anda correspond-
ing internal rib extend from the umbo to the ventral margin. A strong internal
rib passes from the umbo to near the postero-ventral edge.

Posterior to the dorso-ventral groove the shell is ornamented with narrow,
regular concentric ribs; for a short distance in front of the groove the ribs bend
sharply upwards, and soon become smaller and close together ; on the dorsal part
of the anterior end the ribs bend forwards.

Measurements :

(a) (2)
Length : 4 : 14. ‘ 13 mm.
Height : : , hil : 920m.
Thickness : : 12 : KO)

(1—2) Gault, Folkestone.
Affinities —This species resembles 1’. argonnensis (Buvignier),1 but exact
comparison is difficult since only a small internal cast is figured by Buyignier.
The English form appears to differ from 1’. argonnensis im the larger size and
more angular character of the anterior gape, and in the smaller and closer ribs,
especially on the anterior part of the shell.
Distribution.—Lower Gault of Folkestone.

1 «Statist. géol. min. et paléont. de la Meuse,’ Atlas (1852), p. 6, pl. vi, figs. 33—39.

TURNUS. 93!

L
(ve)
Cr

Turnus, sp. Plate XXXVIII, fig. 18.

A specimen from the Upper Greensand of Blackdown resembles the species
from the Gault, described above, but the concentric ribs are finer and more
numerous, and the dorso-ventral furrow is narrower. The exterior of a left valve
only is preserved and is associated with large and rather irregular tubes.

TurNus ? AMPHISBENA (Goldfuss), 1831. Plate XX XVIII, figs. 19, 20.

1822. TrrxEpo, G. Mantell. Foss. 8. Downs, p. 207, pl. xviii, fig. 23.
1831. SeRpuLA AmpHiIsBHNA, A. Goldfuss. Petref. Germ., vol. i, p. 239, pl. Ixx,
fig. 16.
?1839. Crrameycirss, sp., H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 1, p. 15, pls. 1i—vi.
1840. TrREpDO ampuispana, J. de C. Sowerby. Min. Conch., vol. vii, p. 17, pl.
dexviii, figs. 1—5 (Teredo articu-
lata on the plate).
1841. SeRpuLA AmPHISB&ENA, I’. A. Rimer. Die Verstein. d. nord-deutsch.
: Kreidegeb., p. 100.
1842. _ = H. B. Geinitz. Char. d. Schicht. u. Petref. des
siichs.-béhmisch. Kreidegeb., pt. 3,
p- 65.
1843. FisruLANA AMPHISBENA, H, B. Geinitz. Die Verstein. von Kieslingswalda,
p. 11, pl. iv, figs. 11—14.
1845. SerRpuLA AMPHISBHNA, A. HE. Reuss. Die Verstein. der bohm. Kreideformat.,
pt. 1, p. 19, pl. v, figs. 29—32.
1846. Gastrocumna? (TrrEpDO?) ampuispmna, H. B. Geinitz. Grundr. d. Ver-
stein., p. 396.
21850. Fisrunana ampuispana, P. de Ryckholt. Mélanges Paléont. i (Mém. cour.
et Mém. des sav. ¢trang., vol.
xxiv),p.117, pl. v, figs. 19—22.
1850. TerEpo ampuispena, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 354
(p. 385, ed. 2), pl. xxviii, fig. 35.
1851. GasrrocHmNA AMPHISBENA, J. Miller. Petref. der Aachen. Kreidef., pt. 2,
p. 63.
? 1852. - — 2, R. Kner. Denkschr. d. k. Akad. d. Wissensch.
Wien, Math.-nat. Cl. vol. iii,
p. 310, pl. xvi, fig. 18.
1854. Terepo ampuisBxNna, J. Morris. Cat. Brit. Foss., ed. 2, p. 227.
1863. GasrRocH@HNA AMPHISBENA, R. Drescher. Zeitschr. d. deutsch, geol.
Gesellsch., vol. xv, p. 341.
1864. - F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal. Suisse,
ser. 4), p. 19.

CRETACEOUS LAMELLIBRANCHIA.

bo
eu)
jor)

1870. Trrepo AmpuispmnNa, F’. Rimer. Geol. v. Oberschles., pp. 317, 340, pl.
xxxiv, figs. 14, 15.
— GASTROCHHNA AMPHISBHNA, I’, Stoliczka. Paleont. Indica, Cret. Fauna
8. India, pp. 14, 29.
1873. — — H. B. Geinitz. Das Elbthalgeb. in Sachsen
(Paleontographica, vol. xx,
pt. 1), p. 235, pl. lii, figs.

8—12.
1876. — ~ D. Brauns. Zeitschr. f. d. gesammt. Natur-
wiss., vol. xlvi, p. 358.
1877. -- — A. Fritsch. Stud. im Gebiete der béhm.

Kreideformat. 11, Weissenberg. u. Malnitz.
Schicht., p. 122, fig. 93.

1888. — — G. Miller. Jahrb. d. k. preussisch. geol.
Landesanst. fiir 1887, p. 436.
1889. _ — A. Fritsch. Stud. im Gebiete der bohm.

Kreideformat. iv, Teplitz.
Schicht., p. 79, fig. 67.
—— O. Griepenkerl. Senon. vy. Kénigslutter (Pal-
wont. Abhandl., vol. iv),
p- 69, (? pl. vii, fig. 1).

P1889. ? — — EH. Holzapfel. Die Mollusk. Aachen. Kreide
(Paleeontographica, vol. xxxy), p. 143.
? 1893. — = Fritsch. Op. cit. vy. Priesen. Schicht., p. 96,

fig. 113.

?1895. ? — — F’. Vogel. Holliindisch. Kreide, p. 49, pl. i,
fig. 13.
1897. — = R. Leonhard. Kreideformat. in Oberschles.

(Paleontographica, xliy), p.

53, fig. 8.
1898. Turnus AMPHISBHNA, G. Miiller. Mollusk.d. Untersenon v. Braunschweig
u. Ilsede (Abhandl. d. k. preuss. geol.
Landesanst., N. F., Heft 25), p. 79,

pl. x, fig. 12.

1902. — - A. Wollemann. Fauna der Liineburg. Kreide (Ab-
handl. d. k. preuss. geol. Landes-

anst. N. F., Heft 37), p. 81.

Description.—Tubes long, conical, tapering gradually, sometimes nearly straight,
but usually bending or curving irregularly, circular in section, but often com-
pressed, and then showing a median longitudinal furrow on one side. Diameter
sometimes reaches 15mm. andthe length 210mm. Surface with narrow transverse
ridges at more or less regular intervals giving a segmented appearance ; sometimes
also with smaller growth-rings between the ridges.

Remarks.—Vhis species ranges almost throughout the Chalk and is widely
distributed. It has been referred by various authors to five different genera, but

TEREDO. 937

its systematic position must still be regarded as uncertain, for although the tubes
are common the valves have not been found in association with them. Fritsch
(1893) and Miiller (1898) have found the valves of Turns in the same deposit as
the tubes, and think it probable that the former belong to the same species as the
latter. Some authors have referred these tubes to the genus Gastrochena, but
Stoliczka points out that they resemble more nearly the tubes of T'eredo.

Types—From the Senonian of Maestricht and Bochum. The specimens
figured by Sowerby (except fig. 2, which is in the British Museum), by Mantell, and
by Dixon cannot be found.

Distribution —Chloritic Marl of Eastbourne. Cambridge Greensand. Chalk
Marl of Chard and Ventnor. Zone of Holaster subglobosus of Holborough near
Rochester, Totternhoe, Cherry Hinton, and Burwell. Zone of Rhynchonella Cuvieri
of the Devon coast, Winchester, the Isle of Wight, and Lewes. Zone of T'erebra-
tulina of Winchester, the Isle of Wight, Croydon, and Devon. Zone of Holaster
planus of the Dorset coast, the Isle of Wight, Dover, and Luton. Zone of Micraster
cor-testudinarium of Mitcheldever, Dover, the Sussex coast, and Coulsdon (Surrey).
Zone of M. cor-anguinum of the Sussex coast, St. Margaret’s, Thanet, and Graves-
end. Zone of Marsupites testudinarius of Highfield, near Salisbury, the Sussex

coast, and Thanet. Zone of Actinocamar quadratus of the Sussex coast.

Family—TEREDINIDAB, Scacchi.

Genus—Terrepo, Linneus, 1758.
(‘Syst. Nat.,’ ed. 10, p. 651; ed. 12, 1767, p. 1267.)

TEREDO GAULTINA, sp. nov. Plate XXXVIII, fig. 21.

Description. —Shell convex, inequilateral. Anterior gape large, angular.
Postero-ventral gape small. Postero-dorsal margin produced upwards and out-
wards. Umbones large, incurved. A shallow furrow extends from the umbo to
the ventral margin. Posterior to the furrow the shell is ornamented with ribs and
narrow furrows, which soon bend dorsally, and disappear or become indistinct on
the postero-dorsal part; in front of the furrow the ribs are much smaller, and
are parallel to the margin of the anterior gape; at first they are directed dorsally,
but soon bend forwards. Length, 9 mm.; breadth, 8°5 mm.

Affinities—In T. varennensis, Buvignier,' the anterior ribs are coarser and the
posterior end of the shell is more produced than in this species.

Distribution.— Gault of Folkestone.

1 «Statist. géol. min. et paléont. de la Meuse,’ Atlas (1852), p. 6, pl. vi, figs. 40—48.

238 CRETACEOUS. LAMELLIBRANCHIA.

Family—AN ATINIDA, Gray.

Genus—Priecromya, P. de Loriol, 1868.

(De Loriol and Cotteau, ‘Mon. Paléont. Géol. Portlandien de l'Yonne,’ p- 89.)

PLECroMYA ANGLICA, sp. noy. Plate XXXIX, fig. La, b.

Description—Shell elongate-oval, slightly inequilateral, compressed ; anterior
and posterior ends rounded; ventral margin slightly convex. Umbones broad,
with a slight posterior curvature.

The part of the shell in front of a line drawn from the umbo to the opposite
ventral margin is ornamented with strong concentric ribs separated by broad
furrows; these ribs become nearly or quite obsolete on the posterior middle part
of the shell (except near the umbo), but re-appear on the postero-dorsal part.
The entire surface of the shell is ornamented with numerous radial rows of
granules. Length 49 mm.; height 27 mm.

Affinities —This species is similar in general character to Plectomya Agassizi
(VOrbigny'), but the shell is less elongate, the ribs on the anterior part of the
shell cut the margin and the growth-lines obliquely, and on the posterior median
part the ribs are almost obsolete. It also shows some resemblance to P. Rhodani
(Pictet and Roux’).

Remarks.—Ot this species I have seen only two examples, neither of which
shows the interior, so that I am unable to express an opinion as to affinities of the
genus Plectomya.

Distribution. —Lower Greensand (Crackers) of Atherfield.’

Genus—Anatina, Lamarck, 1809.
(‘ Philosoph. Zool.,’ vol. i, p. 319; ‘Hist. nat. Anim. sans Vert.,’ vol. vy, 1818, p. 462.)

Sub-genus—Cerrcomya, L. Agassiz, 1842.
(‘ Etudes crit. Moll. Foss.,’ Myes, p. 143.)

1<Pal. Frane. Terr. Cret.,’ vol. iii (1845), p. 371, pl. ecclxix, figs. 1, 2; Pictet and Campiche,
‘Foss. Terr. Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser. 4, 1865), p. 99, pl. evii, fig. 1.

» * Moll. Foss. Grés verts de Gentve’ (1852), p. 410, pl. xxix, fig. 4.

8 An imperfect specimen from the Lower Greensand of Atherfield is probably an example of
Plectomya marullensis (VOrbigny), op. cit., p. 376, pl. ccclxxi, figs. 3, 4; Pictet and Campiche, op. cit.,

9

p- 101, pl. evii, figs. 2, 3.

Awnatina (Cercomya) curairis, Pictet and Campiche, 1865, Plate XX XIX, figs. 2—4.

1855. Anarrna Ropinatpina, I. J. Pictet and E. Renevier. Foss. Terr. Aptien
(Matér, Pal. Suisse, ser. 1), p. 63, pl. vii, fig. 1.

(Non A. Robinaldina, VOrbigny, 1845.)
1865. curaitis, fF. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),

p. 105, pl. evil, figs. 6—8.
1870. — (Cercomya) Gurattts, EF. Stoliczka. Paleont. Indica, Cret. Fauna

8. India, vol. iii, p. 74.

Description.—Shell elongate, compressed, inequilateral, highest in front of the
umbones, tapermg posteriorly. Anterior margin rounded. Umbones incon-
spicuous, with a carina extending to the posterior extremity. A very shallow
sulcus passes from the umbo obliquely forwards across the valve. In front of this
sulcus the ornamentation consists of narrow, sharp, concentric ribs separated by
broad interspaces ; both ribs and interspaces are crossed by numerous radial rows of
very small pointed projections. Behind the sulcus the concentric ribs become less
distinct or represented by growth-rings only.

Affinities —This species is allied to A. (Cercomya) Robinaldina, VOrbigny,! but
the posterior part of the shell is more elongate.

Remarks.—I1 have seen only three examples of this species. Pictet and
Campiche state that the part of the shell just in front of the carina is ornamented
with radial rows of punctate striz ; these are not seen on the English specimens, pro-
bably on account of their somewhat imperfect preservation. One of our specimens
(Plate XX XIX, fig. 3) agrees very closely, both in the form of the shell and in the
character of the ornamentation, with the figure given by Pictet and Renevier; the
others (figs. 2, 4) approach more nearly the examples figured by Pictet and
Campiche, but the anterior part of the shell is rather higher.

Type.—From the Aptian of the Perte-du-Rhone.

Distribution.—Lower Greensand (Crackers) of Atherfield.

Anatina (CrRcomya), sp. Plate XXXIX, fig. 5a, b.

Description.—Shell very long, compressed, considerably inequilateral, highest
in front of the umbones; posterior part tapering, and curved upwards. Anterior
margin rounded; ventral margin convex; postero-dorsal margin concave. Um-

bones curved posteriorly, with a carina and a shallow furrow extending to the

1 «Pal. Franc. Terr. Crét.,’ vol. iii (1845), p. 374, pl. ceelxx, figs. 6—8.

240 CRETACEOUS LAMELLIBRANCHIA.

posterior extremity. On the anterior part of the shell the ornamentation consists
of narrow, sharp, concentric ribs, which become less distinct on the median and

posterior parts.

Remarl:s.—Only one specimen—an internal cast—has been seen. It resembles
A. (Cercomya) gurgitis, but is more inequilateral and more elongate.

Distribution —Upper Greensand of the Isle of Wight.

Awnatina (Cercomya), sp. Plate XX XIX, fig. 6.

Imperfect specimens of a species of Anatina (Cercomya) have been found in the
Upper Greensand of Warminster and in the Cenomanian (Bed 10) of Dunscombe,
South Devon. In shape they resemble A. (Cercomya) producta, Zittel.'

Genus—Turacia, Leach in H. M.D. de Blaiuville, 1824.
(‘ Dict. Sci. nat.,’ vol. xxxii, p. 347.)

Taracta Puiniips!, Romer, 1841. Plate XX XIX, figs. 7—9.

1829. Mya pepressa, J. Phillips. Geol. Yorks., p. 121, pl. ii, fig. 8 (non M. depressa,
Sowerby, 1823).
1841. Turacia Pururesu, F. A. Rimer. Die Verstein. d. nord-deutsch. Kreide-
geb., p. 74, pl. x, fig. 1.

1850. os recurvVA, A. d’Orbigny. Prodr. de Pal., vol. ii, p.117. (2 T. sub-
depressa, p. 74.)

1854. — Puiuurest, J. Morris. Cat. Brit. Foss., ed. 2, p. 227.

1865. -— — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix

(Matér. Pal. Suisse, ser. 4), p. 120.
— -- rEcURVA, Pictet and Campiche. Ihbid., p. 120.
1870. = — F.. Stoliczka. Palseont. Indica, Cret. Fauna 8. India,

vol. il, p. 72 (Corimya ?).
1875. — Puriiresit, Phillips. Op. cit., ed. 3, p. 254, pl. ii, fig. 8.
1900. — Puituirsi, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.

hollind. Neocoms (Abhandl. d.
k. preussisch. geol. Land., ny. F.,
pt. 31), p. 139, pl. vi, fig. 6.
1905. _— — E. Harbort. Die Fauna d. Schaumburg-Lippe’schen
Kreidemulde (ibid., pt. 45), p. 77.
1908. —- — Wollemann. Jahrb. d. k. preuss. geol. Landesanst.,
fiir 1908, vol. xxix, p. 166.

Description.—Shell thin, more or less ovate in outline, moderately convex, the
right valve a little more convex than the left, shghtly mequilateral. Antero-dorsal
1 «Die Bivaly. d. Gosaugeb.,’ pt. 1 (1864), p. 10 [114), pl. i, fig. 6.

THRACIA. 241]

margin nearly straight, with a considerable ventral slope ; anterior margin rounded,

passing gradually into the convex ventral margin; posterior margin rather short,

oblique, more or less truncated, forming a rounded angle with the nearly straight

and ventrally sloping postero-dorsal margin. Umbones rather prominent, curved

mwards and slightly backwards. Postero-dorsal part of valves compressed, some-

times with a small carina. Surface with numerous small concentric growth-ridges.
Measurements :

(1) (2 (3)
Leneth : 68 : 4. 3 49 mm.
Height 2 52 : 46 : aioh os
Thickness ; 30 ; 28 5 220 es

(1—3) Speeton.

Affinities—It is probable, as maintained by Harbort,! that Thracia striata,
Weerth,* is not specifically distinct from 7. Phillipsi.

Remarks.—The greater part of the shell has disappeared from most of the
examples found at Speeton, and usually some part of the margin of the cast has
also been lost. I have not seen sufficient examples to enable me to determine
whether the variation of this species in England is as great as in the case of the
specimens found in Schaumburg-Lippe and described by Harbort.

Type.—From Speeton, in the York Museum.
Distribution.—Speeton Clay (zone of Belemnites jaculum) of Speeton.

TuHracia RoruNDAtA (Sowerby), 1836. Plate XXXIX, fig. 10a, bd.
1836. Panopma rorunpara, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp. 129, 337, pl. xin, fig. 2.

1850. Lyonsta suprorunpata, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 74.

1854. Myacrres rovunpara, J. Morris. Cat. Brit. Foss., ed. 2, p. 214.

1865. Turacta susrorunpata, F’. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 120.

1870. Corrmya rotrunpara, F. Stoliczka. Paleont. Indica, Cret. Fauna S. India,

vol. il, p. 72.

Description.—Shell regularly convex, oval, slightly inequivalve and inequilateral.
Anterior and ventral margins convex, forming a regular curve. Dorsal part of
posterior margin oblique, forming an angle with the ventral part. Umbones broad,
in contact, with a narrow, sharp, curved carina extending to the posterior angle
and limiting a triangular, concave, postero-dorsal area, which is ornamented with
fine ribs running parallel to the posterior margin. Sides of valves with similar
ribs extending in a radial direction.

1 «Die Fauna d. Schaumburg-Lippe’schen Kreidemulde’ (1905), p. 78.

2 “Neocomsandst. im Teutoburg. Walde’ (‘ Palwont. Abhandl.’ IT, 1884), p. 40, pl. viii, fig. 10.

Wollemann, ‘ Die Bivalyv. u. Gastrop. d. deutsch. u. holliind. Neocoms * (1900), p. 140, pl. vii, fig. 1.
32

242 CRETACEOUS LAMELLIBRANCHIA.

Measurements :

(1) (2)
Leneth ; : 40 : 52 mm.
Height : : 32 : 2 a3
Thickness ; : 22 5 17

(1, 2) Lympne.

Affinities —Vhis species is allied to 7. rotunda, Pictet and Roux,! from the
Gault of the Perte-du-Rhoéne and Sainte Croix, but is distinguished by its more
rounded outline, smaller postero-dorsal area, and less distinct concentric ornament.
It is also allied to 7. cartnifera (p. 244).

Remarks.—-Two internal casts of this species from Lympne are in the Museum
of Practical Geology (23470, 23471); the larger agrees closely with Sowerby’s
figure, and may perhaps be the type, but the locality given by Sowerby is Court-
at-Street, 1} miles west of Lympne. <A small, somewhat crushed example from
the Atherfield Clay at Dover colhery probably belongs to this species. No other
specimens have been seen. The specimens recorded by Topley as 1’. carinifera
probably belong to 7. rotundata.

Distribution.—Hythe Beds of Lympne and Court-at-Street.*

»
».

TuractA Ropinatpina ? (d’Orbigny), 1845. Plate XL, figs. 1

Description.—Shell oval, nearly equilateral; right valve more convex than
the left; posterior part not quite so high as the anterior part; postero-dorsal part
compressed. Anterior margin rounded; ventral margin moderately convex ;
posterior margin shghtly curved; postero-dorsal margin nearly straight. Umbones
rather prominent, curved posteriorly. Surface smooth, except for growth-lines.

Measurements :

(1) (2) (3)
Leneth ; 36 : 26 : 15 mm.
Height : 23 é 17 ; oh es
Breadth : 13 10 6

bb)

(1) Perna-bed, (2, 3) Crackers, Atherfield.

Remarks.—In the English specimens, which are here provisionally referred to
1’. Robinaldina, the shell is preserved, but the examples of that species figured by
dOrbigny® and by Pictet and Campiche' are internal casts, and it is consequently

1 «Moll. Foss. Gres verts de Gentve’ (1852), p. 414, pl. xxix, fig.6. Pictet and Campiche, ‘ Foss.
Terr. Crét. Ste. Croix’ (‘Matér. Pal. Suisse,’ ser. 4, 1865), p. 117.

* Thracia Nicoleti (Agassiz) has been recorded by Morris and by Topley from the Hythe Beds of
Hythe, but I have not seen any British examples of that species.

3 «Pal. France. Terr. Crét.,’ vol. iii (1845), p. 380, pl. ecelxxii, figs. 1, 2.

4 < Foss. Terr. Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser. 4, 1865), p. 114, pl. evi, figs. 5, 6.

THRACIA. 243

difficult, especially without the opportunity of comparing specimens, to establish
the identification. Professor Boule informs me that the type is a poorly preserved
specimen, but that its outline is satisfactorily represented in d’Orbigny’s figure ;
the specimen is now in the Natural History Museum, Paris. 1’. Robinaldina is
allied to 7. neocomiensis (VOrbigny),' but is said to differ from the latter by the
greater curvature of the ventral margin and by its relatively shorter shell.

Distribution —Lower Greensand (Peria-bed and Crackers) of Atherfield.
Atherfield Beds of Redhill, Reigate.

Turacia Sancrz-Crucis, Pictet and Campiche, 1865. Plate XL, fies. 4—6,
1865. Turacra Sancrm-Crocis, F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal. Suisse, ser. 4),
p: 117, pl. eviii, fig. 8.
1870. — — F. Stoliczka. Paleeont. Indica, Cret. Fauna S.
Tudia, vol. iii, p. 72.
Description.—Shell oblong, compressed, imequilateral. Anterior margin
rounded; ventral margin slightly curved; posterior margin truncated, slightly
convex, forming an angle with the postero-dorsal margin. A carina extends in a
curve from the umbo to the postero-ventral angle and cuts off a concave postero-
dorsal area. The surface of the shell is ornamented with growth-rings.
Measurements :

(1) (2)
Length : 7 43 ; 39 mim.
Height , 20 : Gre

(1) Gault, Folkestone.
2) Gault, Black Ven.
Afjinities.—It seems doubtful whether this species is distinct from 17’. stinplex
(VOrbieny), of which casts only are figured by d’Orbigny? and by Pictet
and Campiche®; but the latter authors state that it differs from 7’. simplex by the
absence of an internal rib, the presence of a carina, and by the more acuminate
anterior end.
T'ype.—From the Upper Gault of Ste. Croix.
Distribution.— Gault of Folkestone and Black Ven.

Timacta, sp. Plate XL, figs. 7—9.

Some examples of Thracia, usually of rather large size, appear at first sight to
be distinct from 7’, Sancte-Crucis on account of their relatively greater height and

1 ‘Pal. France. Terr. Crét.,’ vol. iii (1845), p. 381, pl. ccelxxii, figs. 3, 4. Pictet and Campiche,
op. cit., p. 115, pl. eviii, figs. 3, 4.

2 Op. cit., p. 382, pl. ecclxxii, figs. 5, 6.

3 «Boss. Terr. Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser. 4, 1865), p. 116, pl. eviil, fig. 7.

244 CRETACEOUS LAMELLIBRANCHIA.

less distinct cara. When, however, a considerable number of specimens are
compared it is difficult to draw any line of separation between these forms and 7.
Sancte-Crucis. But since, in most cases, the original shape of the shell has been
more or less considerably modified by pressure, it is not easy to come to a definite
conclusion in this matter; moreover, in both 7’. Sancte-Crucis and the larger forms
there is clearly some variation in relative height and length of the shells, and in
the distinctness of the carina.!

Distribution.— Gault of Black Ven and Folkestone. Upper Greensand of
Blackdown and Devizes.

THRACIA CARINIFERA (Sowerby), 1826. Plate XL, figs. 1O—13.

1826. Lurraria? carrnirera, J. de C. Sowerby. Min. Conch., vol. vi, p. 66, pl.
dxxxiy, fig. 2.
1852. — — A. Passy. Descript. géol. de la Seine-Infeér.,
Atlas, p. 6, pl. xin, figs. 6, 7.
1842. Corrmya carinirera, DL. Agassiz. Etudes crit. Moll. Foss., Myes, p. 264.
1845. Lyonsta carinirera, A. d’Orbigny. Pal. France. Terr. Crét., vol. ili, p. 385,
pl. ecelxxiii, figs. 1, 2.
1850. — — A. d’Orbigny. Prodr. de Pal., vol. ii, p. 158.
1852. - — R. Kner. Denkschr. d. k. Akad. d. Wissensch. Wien,
Math.-nat. Cl., vol. iii, p. 311.
1854. Lurrarra carinirera, J. Morris. Cat. Brit. Foss., ed. 2, p. 208 (¢ Thracia).
1865. Turacra carinirera, F. J. Pictet and G. Campiche. Foss. Terr. Cret. Ste.
Croix (Matér. Pal. Suisse, ser. 4), p. 121.
1870. — F. Stoliczka. Palseeont. Indica, Cret. Fauna 8. India,
vol. ii, p. 72.
1893. Lyonsta CARINIFERA, A. Fritsch. Stud.im Gebiete der bohm. Kreideformat.
v. Priesen. Schicht., p. 97, fig. 115.

Description.—Shell thin, oval, of moderate convexity, shghtly inequivalve and
inequilateral. Anterior margin rounded, passing gradually into the regularly
convex ventral margin. Posterior margin truncated, straight or shghtly concave.
Postero-dorsal margin nearly straight. Umbones broad, incurved close together,
with a sharp carina passing to the postero-ventral angle and limiting a flattened
or shehtly concave postero-dorsal area, which is divided in the middle by a shallow,
longitudinal furrow. Just in front of the carina is a broad, shallow, concave
depression.

Ornamentation consists of broad, slightly raised, concentric folds which are
more distinct on the anterior part than elsewhere. On the postero-dorsal area are

1 A similar case of distortion and variation is furnished by Thracia semiplanata, Whiteaves,
‘Mesozoic Foss.’ (‘ Geol. Surv. Canada’), vol. i (1884), p. 221, pl. xxix, fig. 5.

PHOLADOMYA. 245

numerous, fine, regular ribs parallel with the posterior margin ; on the remainder
of the shell similar ribs, but running in a radial direction, occur.
Measurements :

(1) (2) (3) (4)
Length 37 33 f 30 : 20 mm.
Height . : 23 3 22 : 21 : ARs
Thickness. 15 14, — ; 10

2 »
(1) Chalk Marl, Chard.
(2, 4) Chloritic Marl, Devizes.
(3) Chalk Marl, Ventnor.
Afjinities.—In this species the shell is more elongate and less convex, the carina
more prominent, and the postero-dorsal area larger than in 1’. rotwilata (p. 241).
TI’. carinifera is closely allied to 7’. elegans (d’Orbigny),! from the Cenomanian of

St. Sauveur, but is less elongate. 1’. Germari (Geinitz)? from the Senonian, is
regarded by Brauns® as a synonym of 1. carinifera ; but without seeing specimens
of the former it is difficult to express an opinion of its relationship.

Remarks.—The specimens vary considerably in the proportion of length to
height, but in some cases the differences are probably due partly to crushing.
The shell itself is seldom preserved.

Type.—The type came trom the Cenomanian of Dowlands (South Devon) and
was originally in the collection of Sir H. T. De la Beche, but cannot now be
found.

Distribution.—Chloritic Marl of Devizes and Maiden Bradley. Chalk Marl of

Ventnor, Evershot, and Chard.

Family—PHOLADOMYIDAL, Gray.

Genus—Puotavomya, G. B. Sowerly, 1825.

(‘Genera Rec. and Foss. Shells,’ no. xix, pl. xxxvii.)

Puotapomya Cornueniana (d’ Orbiyiy), 1844. Plate XLI, figs. 2u,b, 3.

1844. Carprum Cornvuetianun, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ii,
p- 23, pl. eelvi, figs. 1, 2.

1845. — — E. Forbes. Quart. Journ. Geol. Soc., vol.i, p. 243.

1850. PuHoLrapomya Cornvuetiana, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 117.

1854. Carprum CornvuebianuM, J. Morris. Cat. Brit. Foss, ed. 2, p. 192.
1 * Pal. Frane. Terr. Crét.,’ vol. iii (1845), p. 386, pl. ecelxxiil, figs. 3—5.
2 « Quadersandst. oder Kreidegeb. in Deutschland’ (1850), p. 150, pl. x, figs. 9—11.
3 *Senon. Mergel d. Salzberges,’ Zeitschr. f. d. gesammt. Naturwiss., vol. xlvi (1876), p. 359, pl. x,

figs. 18, 19.

246 CRETACEOUS LAMELLIBRANCHIA,

1855. PHoLtapomya CornuELiAna, F. J. Pictet and E. Renevier. Foss. Terr. Aptien
(Matér. Pal. Suisse, ser. 1), p. 59, pl. vi, fig. 6.
1865. FJ, Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 87.

—- -- H, Coquand. Aptien de Espagne, p. 93.

1870. — —- EF’. Stoliczka. Paleont. Indica, Cret. Fauna 8S.
India, vol. iii, p. 75.
1875. —_ G. Moesch. Mon. Pholadomyen, p. 96, pl. xxxiii,

fig. 8 (? pl. xxxvi, fig. 4).

Description.—Shell_ small, short, oval, inflated, compressed posteriorly,
moderately inequilateral with a small gape at the posterior end. Margins rounded.
Umbones prominent, incurved.

Ornamentation consists of strong, rounded, radial ribs. The grooves between
the ribs are shallow, and broader than the ribs. . Concentric ribs cross the grooves
and ribs, giving to the latter a granulate or tuberculate appearance. Near the
posterior and anterior margins radial ribs are absent.

Measurements :

(1) (2)
Length ' 20 ss, 13 mm.
Height ; 3 16 ; KO) 5

(1, 2) Atherfield.
Affinities.—This species resembles P. Sancti-Sale (Romer)! from Texas and
P. Viguesi, Lartet,* from Palestine, Syria, and Zululand, and LP. subdinensis
(VOrbigny),® from the Cenomanian of Le Mans.
From the Aptian of Wassy (Haute-Marne).
Distribution.—Lower Greensand (Crackers) of Atherfield. Recorded by Topley
from the Atherfield Beds of Peasemarsh and Shalford.

1 "ype.

PHOLADOMYA GIGANTEA (Sowerby), 1836. Plate XL, fig. 14; Plate XLI, fig. 1.

1708. ©. N. Lang, Hist. lapidum figuratorum, p. 146, pl. xliv, fig. 1.
1718. J. J. Scheuchzer, Helvetie hist. nat., pt. 3, p. 307, fig. 113.
1742. L. Bourquet, Traité des Petrific., pl. xxiv, fig. 145.

1 « Kreidebild. vy. Texas’ (1852), p. 48, pl. vi, fig. 7. P. Cornueliana has been compared with
Corbula ewequivalvis, Goldfuss, by Pictet and Renevier, Pictet and Campiche, and Moesch, but Holzapfel
has shown that Goldfuss’ species belongs to the genus Liopistha. Holzapfel, ‘ Die Mollusk. Aachen.
Kreide’ (‘ Paleeontographica,’ vol. xxxv, 1889), p. 150, pl. ix, figs. 4—6; Miiller, ‘ Mollusk. d. Untersenon
v. Braunschweig u. Ilsede’ (1898), p. 76, pl. x, fig. 9.

2 «Explor. géol. de la Mer Morte’ (1877), p. 126, pl. xi, fig. 9; Blanckenhorn, ‘ Beitr. z. Geol.
Syriens’ (1890), p. 94, pl. v, figs. 14—17; Kossmat, ‘Denkschr. d. k. Akad. Wiss., Wien,’ vol. ]xxi
(1902), p. 55, pl. iv, fig. 9; Newton, ‘Trans. Roy. Soe. 8. Africa,’ vol. i (1909), p 79, pl. vi, figs. 3—6.

3 «Pal. Frane. Terr. Crét.,’ vol. iii (1844), p. 38, pl. ecl, figs. 1—3. An internal cast resembling
P. subdinensis has been found by Mr. J. Scanes in the Chloritic Marl of Maiden Bradley.

PHOLADOMY A. 247

1836. Puozas GIGANTEUs, J. de C. Sowerby. Trans. Geol. Soe., ser. 2, vol. iy,
130, 338, pl. xvi, fig. 1.
1840. PHonapomya ELONGATA, A. foldfuss. Petref. Germ., vol. 1i, p. 270, pl.

elvii, fig. 3.

pp:

1842. —— — L. Agassiz. Etudes crit. Moll. Foss., Myes, p. 57,
pl. i, figs. 16, 17.
— — Scuevcuzert, Agassiz. Ibid., p. 58, pl. iil, figs. 3—7, pl. ui),
fie. 7.
-— -- Favrina, Agassiz. Thid., p. 59, pl. ii}, figs. 1, 2.
— _ Laneu, Voltz, in Leymerie. Mém. Soe. gvol, de France, ser, 2,
vol. v, p. 24.
1845. — ELONGATA, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii,

p- 390, pl. ecelxii.
- — GIGANTEA, I. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 238.
1850. — ELONGATA, @ Orbigny. Prodr. de Pal., vol. Hepa:

1852. — Favrina, F’. J. Pictet and W. Roux. Moll. Foss. Grés verts
de Gentve, pp. 403, 546, pl. xxix, fig. 1.

1854. -- GIGANTEA, J. Morris. Cat. Brit. Foss., ed. 2, p. 220.

1855. — ELONGATA, G, Cotteau. Mbll. Foss. de l’Yonne, p. 55.

—- — — F. J. Pictet and E. Renevier. Foss. Terr, Aptien
(Matér. Pal. Suisse, ser. li) sp: 6.

1858. _— J.Vilanova-y-Piera. Mem. geog.-agric. de Castellon,
pl. iii, fig. 16.

1861. a — P. de Loriol. Anim. Invert. Foss. Mt. Saltve, p. 56.

1864—65, — — FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse, ser. 4),
p- 74, pl. civ, figs. 1—4.

1870. — GIGANTEA et ELONGATA, F’. Stoliczka. Paleont. Indica, Cret.

Fauna 8. India, vol. iii, p. 74.

1875. — GIGANTEA, C, Moesch. Mon. Pholadomyen, p. 82, pl xxx, fig.
6; pl. xxi, figs. 2—4.

1884. — cf. GIGanTEA, O. Weerth. Die Fauna des Neocom. im Teuto-

bure. Walde (Paleont. Abhandl., vol. il),
p. 34, pl. viii, figs. 2, 3.

1895. — Weerruu, F. Vogel. Hollindisch, Kreide, p. 59.
—_ _ ELONGATA, G. Maas. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xlvii, p. 279, pl. ix, figs. 1, 2.
1896. — — A. Wollemann. Ibid., vol. xlviii, p- 850.
1900. — — A. Wollemann. Die Biv. u. Gastrop. d. deutsch.

u. holliind. Neocoms (Abhandl.
d. k. preussisch. geol, Land.,
N.F., pt. 31), p. 133
_- — — G. Miiller. Deutsch-Ost-Afrika, vol. vil, p. 557,
pl. xxi, fig. 1,

1903. a -- C. Burckhardt. Paleontographica, vol. 1, p. 76,
pl. xv, figs. 1, 2.
1908. — — A. Stojanof. Ann. géol. et min. de la Russie, vol.

xe LLG:

248 CRETACEOUS LAMELLIBRANCHIA.

Shell large, elongate, somewhat arched, convex, but with the sides

Description.
of the posterior part more or less flattened, very inequilateral, with a large gape
at the posterior end. Anterior part short, with a rounded margin. Ventral margin
curved. Posterior margin subtruncate, rounded. Postero-dorsal margin long,
slightly concave or almost straight. Umbones broad. Near the umbones the
antero-dorsal and postero-dorsal marginal parts of the shell are depressed.

Ornamentation consists of numerous narrow, sharp, prominent and sometimes
slightly serrate radial ribs, which are straight or slightly curved. Near the
anterior and the postero-dorsal margins ribs are absent ; on the postero-dorsal part
of the shell they are rather more widely separated and rather more prominent
than on the median part. Between the ribs are broad, concave furrows which are
crossed by numerous growth-lines.

Measurements :

(1) (2)
Length : : 126 : 122 mm.
Height : ; 63 : 60" ss

(1, 2) Crackers, Atherfield.

Affinities —The elongate form and numerous sharp ribs distinguish this from
other Cretaceous species of Pholadomya.

Remarks.—The foreign examples of this species show considerable variation in
length, in the curvature of the shell, and in the number of ribs. Some of the
varieties have been described as distinct species, but Pictet and Campiche have
shown that there are numerous transitions between the different varieties. The
English examples agree in most cases with the type of the species, but some
approach the variety described by Agassiz as P. Scheuchzert. A specimen figured

by Moesch shows the large pallial sinus.

T'ype.—The type came from the Hythe Beds of Court-at-Street, but cannot now
be found.
Distribution.— Lower Greensand (Crackers) of Atherfield. Atherfield Beds of

East Shalford. Hythe Beds of Court-at-Street and Lympne.

PHOLADOMYA SPEE'TONENSIS, sp. nov. Plate XLI, fig. 4a, b.

Description—Shell large, oval, short, inflated, very imequilateral. Anterior
margin rounded; ventral margin convex. Umbones broad, incurved.

Ornamentation consists of numerous (usually about twenty-one) strong, radial

=?
ribs, separated by broad, slightly concave interspaces. Secondary ribs are intro-
duced at a short distance from the umbo, and usually soon become as large as the
primary ribs. The ribs are more or less nodular. Concentric growth-lmes are
present. Two or three of the anterior ribs are more widely separated than the
others. On the postero-dorsal and the anterior parts of the shell ribs are absent.

PHOLADOMYA. 249

Affinities —By some authors this species has been identified with P. Martini,
Forbes. With the material at present available it is difficult to make a satisfactory
comparison ; but the specimens from Speeton are of considerably larger size, with
broader and less prominent umbones, and with the posterior part of the shell less
compressed than in P. Martini.

In form this species resembles P. alternans, Rémer,' but the umbones are
relatively higher, and the radial ribs more numerous. ‘The ribs are not so numerous
as in P. Hberti, Wollemann.?

Remarks.—The specimens from the clays are considerably crushed, whilst in
those from the hard nodular beds a more or less considerable portion of the

marginal part of the shell is missing.
Distribution.—Speeton Clay (zones of Belemuites lateralis, B. jaculum, and BD.
brunsvicensis) of Speeton.

Puotapomya Martimnt, Forbes, 1845. Plate XI, fig. 5.

1845. Pronapomya Marrint, H. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 2338,
pl. ii, fig. 3.

1850. = o A. dOrbigny. Prodr. de Pal., vol. 1, p. 117.
1854. -- -- J. Morris. Cat. Brit. Foss., ed. 2, p. 220.
1865. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4), p. 92.
? 1908. — -- A. Wollemann. Jahrb. d. k. preuss. geol. Landes-

anst. fiir 1908, vol. xxix, p. 165,
pl. x, fig, 3.

Description.—Shell rather small, oval, very inequilateral, anterior part inflated,
posterior part compressed. Umbones prominent. Escutcheon.deep. Ornamenta-
tion consists of numerous radial ribs, which are more or less tuberculate, and are
more widely separated anteriorly than on the median part; on the anterior and
postero-dorsal parts ribs are indistinct or absent. Concentric ribs and growth-lines
are present.

Remarks.—It is difficult to give a satisfactory description of this species, since
the specimens seen are few in number, imperfectly preserved, and usually crushed.
P. Martini appears to be closely allied to P. Fabrina, VOrbigny (see below). Ib
also resembles P. hispanica, Coquand.*

1 Wollemann, ‘ Die Biv. u. Gastrop. d. deutsch. u. holliindisch. Neocoms’ (1900), p. 134, pl. v, figs,
g, 10; pl.vi, fig. 3. Specimens with fewer ribs from the Spilsby Sandstone and the Claxby Ironstone
of Lincolnshire approach P. alternans more nearly than do the specimens from Speeton

> Thid., p. 136, pl. vi, fig. 4.

8 «Mon. Aptien de l’Espagne’ (1865), p. 92, pl. vii, figs. 5, 6.

ee
we)

250 CRETACEOUS LAMELLIBRANCHIA.

Type.—From the Hythe Beds of Pulborough. A specimen which is believed to
be the type, but which is more crushed dorso-ventrally than is indicated by the
figure, is in the Museum of the Geological Society (No. 2197).

Distribution—Lower Greensand (Perna-bed and Crackers) of <Atherfield.
Hythe Beds of Pulborough.

Puotapomya Farina, d’Orbigny, 1845. Plate XLI, fig. 6.
1845. PHorapomya Fasrina, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. i, p.

354, pl. ecelxii, figs. 6,7. (Non
P. Favrina, Agassiz, Pictet and

Roux.)

1850. -— — d’ Orbigny. Prodr. de Pal., vol. ii, p. 135.
1865, ~- a F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4), p. 92.
1897. -- Favrina ?, R. B. Newton. Proc. Dorset Nat. Hist. and
Antiq. Field Club, vol. xviii,

p- 92.

? Non 1874. — Farina, C. Moesch. Mon. Pholadomyen, p. 94, pl. xxxii, fig. 1.

Remarks.—Some crushed specimens found in the Gault are probably examples
of P. Fabrina, d’Orbigny. They resemble P. Martini, but have coarser and more
distinctly tuberculate ribs, and the concentric rings appear to be more conspicuous.

Distribution.—Gault of Black Ven, Okeford Fitzpaine, and Folkestone.

PuHoLapomya pECcusSATA (Mantell), 1822. Plate XLI, figs. 7—9; Plate XLII, fig. 1.

1822. Carprium? precussatum, G. Mantell. Foss. S. Downs, p. 126, pl. xxv, fig. 3.
27 -- — J. de C. Sowerby. Min. Conch., vol. vi, p. 99, pl.
dlii, fig. 1.
1837. — -— A. Goldfuss. Petref. Germ., vol. ii, p. 222, pl. exly,
fig. 2.
~- PuHotapomya peEcussata, G. G. Pusch. Polens Paliiont., p. 87,
1841. Carpium precussatum, F. A. Rimer. Die Verstein. d. nord-deutsch.
Kreidegeb., p. 71.
1846. PHonapomya prcussata, A. EH. Reuss. Die Verstein. der bohm. Kreide-
format., pt. 2, p. 17.
1850. —— — J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 355
(p. 385, ed. 2), pl. xxix, fig. 6.
— — _ H. B. Geinitz. Das Quadersandst. oder Kreidegeb.
in Deutschland, p. 146.
— _— R. Kner. Verstein. d. Kreidemergels v. Lemberg
(Haidinger’s Naturwiss. Abhandl.,
vol. ii, pt. 2), p. 24.

PHOLADOMYA. 25]

1850. PHonapomya pecussara, A. Alth. Geogn.-palwont. Beschreib. v. Lemberg

? 1898.

1901.

1902.

Non 1829.

— 1842.

— 1843—50.

— 1849.

(ibid.), p. 236.
J. Morris. Cat. Brit. Foss., ed. 2, p. 220.
var. TRIANGULARIS, H. G. Seeley. Ann. Mag. Nat.
Hist., ser. 3, vol. vii, p. 122.

(Carpium) pEcussara, A. v. Strombeck. Zeitschr. der deutsch.

geol. Gesellsch., vol. xv, p. 143.

pecussata, F. J. Pictet and G. Campiche. Terr. Crét. Ste.

Croix (Matér. Pal. Suisse, ser. 4), p. 94.
E. Favre. Moll. Foss. de la Craie de Lemberg,
p- 106.
A. J. Jukes-Browne. Quart. Journ. Geol, Soc.,
vol. xxxi, p. 300.
C. Moesch. Mon. Pholadomyen, p- 107, pl. xxxii,
figs. 5 ?,6; pl. xxxvi, figs. 5, 6.
D. Brauns. Zeitschr. f. d. gesammt. Naturwiss.,
vol. xlvi, p. 361.
E. Holzapfel. Die Mollusk. Aachen. Kreide (Pal-
wontographica, vol. xxxv), p- 154,
pl. xiv, figs. 3, 4.
J. Bohm. Kreidebildung. d. Fiirbergs u. Sulz-
bergs (Paleontographica, vol. xxxviii), p- 73.
A. Fritsch. Stud. im Gebiete der béhm. Kreide-
format. v. Priesen. Schicht., p. 97, fig. 116.
G. Miller. Mollusk. d. Untersen. y. Braunschweig
u. Ilsede, p. 74, pl. x, fig. 3.
A. Wollemann. Jahrb. d. k. preuss. geol. Landes-
anst. fiir 1900, vol. xxi, p. 22.
A. Wollemann. Liineburg. Kreide, p. 79.

J. Phillips. Geol. Yorks., pp. 122, 186 (p. 255,
ed. 3), pl. ii, fig. 9.
L. Agassiz. Etudes crit. Moll. Foss., Myes, p. 74,
pl. iv, figs. 9,10; pl. iv}, figs. 7—11.
G. P. Deshayes. Traité Elément. de Conchyliol.,
vol. i, pt. 2, p. 158, pl. v, fig. 5.
A. @Orbigny. Prodr. de Pal., vol. i, p. 335.

Distribution.—Shell large, inflated, with the greatest diameter at the anterior

end, outline semi-ovate (sometimes sub-trigonal), wedge-shaped behind, extremely

inequilateral, with a small posterior gape; height and length often nearly equal.
Posterior margin rounded. Anterior part of the

Ventral margin slightly curved.

shell very short, flattened, with cordate outline, nearly perpendicular to the plane
between the valves, and forming almost a right angle with the sides of the valves ;
the margin of the anterior part is more or less angular, and just within is a
shallow concave part parallel to the margin, whilst the median part is convex, and

252 CRETACEOUS LAMELLIBRANCHIA.

that near the umbones is depressed. Umbones curved considerably inwards and
more or less forwards. Escutcheon depressed.

Ornamentation consists of narrow radial ribs separated by broad, shallow
depressions. Ribs are absent from the posterior part of the shell, and from the
anterior flattened part, except near its margin; they become smaller or disappear
altogether near the ventral margin. Well-marked growth-rings occur over the
entire surface of the shell, but are more distinct near the umbones than ventrally,
and give a granular or nodular appearance to the radial ribs, especially on the
dorsal part of the shell.

Measurements :

(1) (2) (3)
Length ; : 98 2 60 : 54 mm.
Height 4 ’ 74 59 E Oa oe
Thickness . 65 51 ; 49 ,,

(1, 2) Chalk Marl, Ventnor.
(3) Chalk Marl, Eastbourne.

Affinities —The smaller forms of this species show some resemblance to P.
genevensis, Pictet and Roux,' from the Gault, but the concentric rings are less
prominent, and the valves more inflated and less distinctly triangular. Another
similar form is ?. Malbosi, Pictet.2. See also P. cordata (below).

The specimens from the Cambridge Greensand were regarded by Seeley as
constituting a variety (P. decussata var. triangularis), but, as was pointed out by
Jukes-Browne, they agree in all essential characters with P. decussata, differing
only in their smaller size. Specimens of P. decussata found in the Gault of
Folkestone are larger than those found in the Cambridge Greensand, but not so
large as the examples in the Chalk.

Remarks.—In England this species has not been found above the Cenomanian
(zone of H. subglobosus), but on the Continent it appears to range up into the
Senonian. In many of the English specimens the original shape has been modified
by crushing, and that also appears to be the case with some of the examples
figured by foreign authors.

Type-—The type from the Lower Chalk near Brighton, and the specimen
fioured by Sowerby from the Chalk Marl of Hamsey, and the one figured by
Dixon, cannot now be found.

Distribution. Gault of Folkestone. Cambridge Greensand. Chalk Marl of
Ventnor, Culver Cliff, Eastbourne, Hamsey, Middleham, Offham, Glynde and
Folkestone. Totternhoe Stone (zone of Holaster subglobosus) of Arlesey and
Burwell.

1 «Moll. Foss. Grés verts de Gentve’ (1852), p. 405, pl. xxix, fig. 2. Moesch, ‘Mon. Phola-
domyen’ (1875), p. 97, pl. xxxil, figs. 2—4.

2 «Mélanges Paléont.’ (1868), p. 92, pl. xix, fig. 3. Moesch, op. cit., p. 88, pl. xxx, fig. 5, pl. xxv, fig. 1,

MYOPHOLAS. 253

Puotapomya corpata, Tate, 1865. Plate XLII, fig. 2 a—e.

1865. PHorapomya corpara, R. Tate. Quart. Journ. Geol. Soc., vol. xxi, p. 40,
pl. iv, fig. 1.

Remarks.—A specimen found in the Upper Chalk (zone of Belenmitella mucro-
mata), now in the Norwich Museum (No. 3339), is probably an example of P.
cordata, bat unfortunately the anterior part of the shell is imperfect. In this
species the anterior curvature of the umbones is greater and the depression in
front of them deeper than in P. decussata; also the anterior flattened part is
relatively smaller, since the greatest diameter of the shell occurs at about one third
of the length from the anterior end. The types of P. cordata from the Upper
Chalk of Ireland are in the Museum of Practical Geology (Nos. 23.628 ; 25,629).

Genus—Myornoias, H, Douvillé, 1907.

(‘ Bull. Soe. géol. de France,’ ser. 4, vol. vii, p. 107.)

Myopuonas, sp. cf. semicostara (Agassiz), 1842. Plate XLII, fig. 3a, b.

Description.—Shell oval, short, considerably inequilateral, anterior part convex,
posterior part compressed; anterior and posterior margins rounded. Umbones
curved inwards and forwards. Rather more than half of the shell—the anterior
part—is ornamented with thirteen narrow, sharp, radial ribs, which are separated
by broad, flat, or slightly concave interspaces; posteriorly these ribs become
smaller and less widely separated; on the middle part of the shell a few indistinct
concentric ribs are seen. The posterior part of the shell is nearly smooth, and is
separated from the ribbed area by a slight depression; a curved carima extends
from the posterior side of the umbo towards the postero-ventral extremity.

Affinities —Only one specimen has been seen; it resembles closely M. semi-
costata (Agassiz'), but is rather shorter, and the posterior limit of the ribbed area
is more sharply defined than in most examples of M. semicostata. Judging from
1 «Etudes crit. Moll. Foss.,’ Myes (1842), p. 51, pl. ii, figs. 1, 2, pl. iii!, fig. 11. Pictet and
Campiche, ‘ Foss. Terr. Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser. 4, 1865), p. 77, pl. ev, figs. i 2.
Moesch, ‘ Mon. Pholadomyen’ (1874), p. 85, pl. xxx, fig. 4, pl. xxxiii, figs. 3, 4, pl. xxxvi, fig. 1.
Douvill¢, ‘ Bull. Soc. géol. de France,’ ser. 4, vol. vii (1907), p. 112, pl. ii, fig. 8. Moesch includes as
a synonym Pholadomya Triboleti, Pictet and Campiche, op. cit., p. 89, pl. evi, fig. 8. Pictet and
Campiche include P. Moreana, Buvignier, ‘ Statist. géol., ete., de la Meuse * (1852), Atlas, p. 8, pl. viii,
figs. 21, 22.

254, CRETACEOUS LAMELLIBRANCHIA.

the figures given by several authors, that species varies considerably, so that it
seems probable that when more English specimens have been obtained it will be
possible to refer them definitely to M. semicostata.

Distribution.—Lower Greensand of Furze Hill, Faringdon.

Genus—Gontomya, L. Agassiz, 1842.
(‘ Etudes crit. Moll. Foss.,’ Myes, pp. xii, 1.)

Goniomya Arcutact (Pictet and Renevier), 1855. Plate XLII, figs. 4, 5.

1855-6. Turacta Arcutact, F’. J. Pictet and E. Renevier. Foss. Terr. Aptien
(Matér. Pal. Suisse, ser. 1), p. 67,
pl. vii, fig. 5.
1858. — -- Pictet and Renevier. Ibid., p. 176.
1865. PHotapomya tTHRaAcrorpEs, F. J. Pictet and G. Campiche. Terr. Crét. Ste.
Croix (Mater. Pal. Suisse, ser.
4), p. 92 (Goniomya).
1870. Gontomya Arcutact, FI’. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,

vol. i, p. 75.

Description.—Shell oblong, convex, nearly equilateral. Anterior margin
rounded. Ventral margin slightly convex or nearly straight, nearly parallel with
the dorsal margin. Posterior margin truncated, oblique, slightly convex, forming
a rounded angle with the ventral margin and an obtuse angle with the postero-
dorsal margin. Umbones of moderate size, with a faint rounded carina extending
postero-ventrally, above which the shell is compressed; lunule and escutcheon
elongate, depressed, limited by carine.

Ornamentation: Anteriorly to the umbones there is a ribbed area in which the
ribs extend obliquely backwards; posteriorly to the umbones is another ribbed area
in which the ribs are nearly perpendicular to the postero-dorsal margin, but
slightly curved ventrally. The anterior, ventral, and postero-dorsal parts of the
shell are without ribs, and show growth-lines only. Near the umbo the ribs of
the two areas are connected by horizontal ribs, but ventrally these horizontal ribs
are absent or indistinct. Some parts of the shell are marked by rows of small
pits.

Measurements :

(1) (2) (3)
Length : : 33 : 28 ; 19 mm.
Height : : 19 16 : 11

9

(1—3) Crackers, Atherfield.

GONIOMYA. 255

Affinities.—This species is less inequilateral, and the ribs are less extensively
developed than in (. caudata, Agassiz.}
Remarks.

English examples of this species were identified by Pictet and
Renevier, who state that the forms referred by Forbes? to Pholadomya Agassizi
are really specimens of G. Archiaci.

Type.—F¥rom the Aptian of the Perte-du-Rhéne.

Distribution. Lower Greensand (Crackers) of Atherfield.’

GontomyA Maintnnana (d’Orbigny), 1845. Plate XLII, figs. 6, 7.

1845. PHorapomya Mariieana, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii,
p- 359, pl. ecelxiv, figs. 1, 2.
1845. Gonromya Maruieana, L. Agassiz. Etudes. crit. Moll. Foss., Myes, p. xiv.
1850. PHotapomra Mariieana, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 157.
1854. PHotapomya Mariieana, J. Morris. Cat. Brit. Foss., ed. 2, p. 220.
1865. — — F. J. Pictet and G. Campiche. Terr. Crét. Ste.
Croix (Mater. Pal. Suisse, ser.
4), p. 93 (Goniomya).
? 1868. PHonapomya Maiiurana, A. Briart and F. L. Cornet. Meule de Bracque-
enies (Mém. cour. et Mém. des
Sav. ¢trangers, vol. xxxiv), p. 83,
pl. vi, fig, 12.
1870. Gontomya Martieana, F. Stoliczka. Paleont. Indica, Cret. Fauna S.
India, vol. iii, p. 75.
? 1885. PHotapomya (Gontomya) Mariurana, F. Nitling. Die Fauna d. baltisch.
Cenoman. (Paleont. Abhandl.,
vol. ii), p. 36, pl. vi, fig. 9.

Description.—Shell elongate, subquadrate, convex, very equilateral. Anterior
part not so high as the posterior part, compressed, with rounded margin.
Antero-dorsal margin concave. Postero-dorsal margin long, nearly straight, and
nearly parallel to the slightly convex ventral margin. Posterior margin truncated,
oblique, forming a rounded angle with the ventral margin, and an obtuse angle
with the postero-dorsal margin. Umbones pointed, directed anteriorly. Lunule
concave, elongate-ovate, limited by a carina. Escutcheon long, deep near the
umbones, limited by a carina. Between the carina of the escutcheon and a
rounded ridge extending from the umbo towards the postero-ventral margin the
shell is concave.

1 «Etudes crit. Moll. Foss., Myes (1842), p. 22, pl. 1b, figs. 1—3, pl. i, fig. 1. Pholadomya
Agassizi, d’Orbigny, ‘Pal. Franc. Terr. Cret.,’ vol. iii, p. 352, pl. ecelxiii, figs. 1, 2; Pictet and
Campiche, ‘ Foss. Terr. Crét. Ste. Croix’ (‘ Mat¢r. Pal. Suisse,’ ser. 4, 1865), p. 84, pl. evi, figs. 4—6.

2 «Quart. Journ. Geol. Soe.,’ vol. i (1845), p. 289. Morris, ‘ Cat. Brit. Foss.,’ ed. 2 (1854), p. 176.

8 An imperfect specimen of Goniomya from the Tealby Limestone of Claxby is in the Sedgwick
Museum, Cambridge.

256 CRETACEOUS LAMELLIBRANCHIA.

Ornamentation consists of rounded ribs; those in front of the umbones are
nearly straight and slope obliquely backwards and downwards ; those behind the
umbones are curved and more or less nearly parallel to the posterior and postero-
dorsal margins; near the ventral margin the ribs become more nearly concentric
and are often less distinct (especially on the median part) than on the dorsal
portion of the shell.

Affinities —This species differs from G. designata (Goldfuss)' in the smaller
curvature of the ventral margin, and in the truncated form of the posterior
margin. It is closely allied to G. consignata, Rémer,*? but the anterior curvature
of the umbones is more marked.

Remarks.—This species has been identified by comparison with a specimen

given me by M. Raoul Fortin from the same locality as the type.
T'ype.—From the Cenomanian of Mte. Ste. Catherine, Rouen.
Distribution.—U pper Greensand (zone of Schlaenbachia rostrata) of Blackdown,

Devizes, and near Maiden Bradley. Base of Chalk Marl of Chard.*

Family—PLEUROMYIDA, Zittel.

Genus—Prevromya, [. Agassiz, 1842.
(‘ Etudes crit. Moll. Foss.,’ Myes, p. 231.)

Preoromya Orpientana (Rouillicr), 1847. Plate XLITI, figs. 1, 2a—e.

1847. Panopma Orprentana, C. Rowillier. Bull. Soc. Imp. Nat. Moscou, vol. xx,
p. 407; vol. xxi (1848), p. 28],
pl. G, fig. 24.

Description.—Shell oval, convex, inequilateral, with a small posterior gape.
Anterior and posterior margins rounded. Ventral margin considerably convex.
Umbones moderately prominent, incurved. Shell depressed in front of and behind
the umbones. “Surface nearly smooth, but ornamented with linear, radial ribs,
which are sometimes parallel, sometimes irregular; in some places the ribs are
replaced by rows of minute tubercles.

Affinities—The English specimens agree closely with examples from the Lower

1 « Petref. Germ.,’ vol. ii (1840), p. 264, pl. cliv, fig. 13. Holzapfel, ‘ Mollusk. Aachen. Kreide’
(Paleontographica, vol. xxxv, 1889), p. 153.

2 «Die Verstein. d. nord-deutsch. Kreidegeb.’ (1841), p. 75, pl. x, fig. 3. Miller, ‘ Mollusk.
Untersen. v. Braunschweig u. Ilsede’ (1898), p. 71, pl. x, fig. 7.

8 A small specimen of Goniomya has been found in the Chalk of Trimingham by Mr. R. M.

Brydone.

LIOPISTHA. 257

Volgian of Moscow, which were identified by Prof. Pavlow, but their resemblance
to Rouillier’s figure is not quite so close. Some of the smaller specimens approach
P. peregrina (VOrbigny'), which is said to differ from P. Orbigniana by smaller
curvature of the ventral margin, the presence of a shallow depression extending to
the ventral margin below the umbones, and by the ornamentation consisting of
radial rows of minute tubercles instead of linear ribs. One specimen from Spilsby,
however, shows both types of ornamentation, suggesting that the two species are
not really distinct. The hinge is not seen in any of the English specimens of P.
Orbigniana, but the figure given by Rouillier, although not quite satisfactory, is
suggestive of Panopea; the form of the shell, however, resembles that of some
Jurassic species of Plewromya.
Distribution.—Spilsby Sandstone (zone of Belemnites lateralis) of Donnington.

Family—POROMYACIDA, Dall.

Genus—LriopistHa, I’. B. Meek, 1864.

(‘Check List Invert. Foss. N. America,’ pp. 12, 32; T. A. Conrad in Kerr’s ‘ Report Geol. Survey
N. Carolina,’ vol. i, 1875, Appendix A, p. 28; Meek, ‘Invert. Cret. and Tert. Foss. U. Missouri,’
1876, p. 227.)

Section—Pstromya, Meek, 1876.
(Ibid., p. 229.)

LiopisrHa (Pstnomya) Gicanrea (Sowerby), 1818. Plate XLITII, figs. 3, 4; Plate
OGL, fies: 15,2:

1811. Corsuna ?, J. Parkinson. Organic Remains, vol. iii, p. 226.

1818. — GIGanTEA, J. Sowerby. Min. Conch., vol. iii, p. 13, pl. ecix,
figs. 5—7.

1850. PHoLtapomya — A. dOrbigny. Prodr. de Pal., vol. ii, p. 157.

1854. THETIS _ J. Morris. Cat. Brit. Foss., ed. 2, p. 227.

1865. — ? -= F. J. Pictet and G. Campiche. Terr. Crét. Ste. Croix

(Matér. Pal. Suisse, ser. 4), pp. 199, 210.

1870. PoromyaP — F. Stoliczka. Palewont. Indica, Cret. Fauna 8. India,
vol. iii, p. 42.

1882. LiopistHA — P. de Loriol. Gault de Cosne, p. 45, pl. vi, figs. 1—5.

1 Murchison, Verneuil, and Keyserling, ‘Géol. de la Russie de l'Europe,’ vol. ii (1845), p. 468,
pl. xl, figs. 10O—12. The hinge is figured by Zittel, ‘Handbuch d. Paliiont.,’ vol. ii, p. 125, fig. 179,
and ‘ Grundziige d. Paliiont.,’ ed. 2 (1903), p. 330, fig. 732.
J+

258 CRETACEOUS LAMELLIBRANCHIA.

Description.—Shell large, rather thick, oval, elongate, inflated, the posterior
part compressed, very inequilateral. Anterior part very short, with rounded
margin, but its dorsal part only shghtly curved. Ventral margin forming a
considerable curve. Posterior margin obliquely truncated, more or less rounded.
Postero-dorsal margin nearly straight. .Umbones large, prominent, pointed,
inrolled, and with a more or less considerable forward curvature. A rounded
carina extends from the front of the umbones to the middle of the anterior margin
and forms the boundary of a deeply excavated area in front of the umbones.

Ornamentation consists of broad, rounded, concentric ribs on the dorsal part
of the valves except on the anterior excavated area. In passing ventrally these
ribs become less prominent and are soon represented by concentric lines. Rather
’ widely separated radial rows of minute tubercles are present and leave small pits
when broken off. Near the umbo small radial ribs are present.

Measurements :

(1) (2) (3)
Length 5 : 128 : 110 é 90 mm.
Height ; : 89 : 82 : [s1>

(1—3) Blackdown.

Affinities —This species resembles L. (Psilomya) superba (Stoliezka'), but
differs in outline, in the concentric ribs bemg confined to the dorsal part of the
shell, and in the less inflated form of the valves.

Remarks.—In the small examples of this species the shell is relatively shorter
and more nearly orbicular in outline and the concentric ribs cover the whole
or nearly the whole of the valves. The radial ribs near the umbo are seen
in only a few specimens.

T'ype.—From Blackdown, in the British Museum.

Distribution.—Upper Greensand (zone of Schlenbachia rostrata) of Blackdown.

LioristHa, sp. Plate XLIII, fig. 5a—e.

Description.—Shell oval, slightly inequilateral, inflated, posterior part com-
pressed, with a shallow furrow near the postero-dorsal margin, concave in front
of the umbones. Anterior and posterior margims rounded; ventral margin
considerably convex. Umbones prominent, curved inwards and forwards.

Ornamentation consists of numerous (about twenty-nine), narrow radial ribs
bearing small tubercles, and separated by concave interspaces of greater breath
than the ribs. On the postero-dorsal part of the shell ribs are absent. The
ribs are crossed by faintly marked concentric rings.

Remarks.—The only example of this species which has been seen does not

1 «Paleeout. Indica, Cret. Fauna 8. India’ (1870), p. 48, pl. i, figs. 2—4.

CUSPIDARIA. 259

show the hinge, but it is provisionally referred to Liopistha on account of its
external resemblance to some species of that genus.! It should be noted, how-
ever, that it is also similar to some species which are believed to belong to the
genus Pholadomiya.

Distribution.—Red Limestone of Hunstanton.

Family—CUSPIDARIID AS, Dall.

Genus—Cuspipanta, G. D. Nardo, 1840.

(‘ Ann. Sci. Lombardo-Veneto,’ vol. x, p. 49.)

Cuspiparia Sanauptana (Pictet and Campiche), 1864. Plate XLIII, fig. 6a,);
Plate XLIV, fig. 3a, b.

1864. Nemra Sasauprana, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 4),
p. 40, pl. ¢, figs. 5

7.

Description.—Shell inflated, oval, oblique, slightly mequivalve, anterior part
sloping rapidly to the margin, posterior part compressed and produced into a
pointed beak. Anterior margin rounded; ventral margin convex, curving upwards
and passing gradually into the posterior margin. Umbones curved inwards and
slightly backwards. A narrow postero-dorsal area is bent at an angle with the
sides of the shell, and is limited by a carina.

Ornamentation consists of strong, concentric ribs, most of which are con-
tinued on to the posterior beak, where they become rather smaller and closer
together ; on the sides of the ribs and in the furrows are a few faint concentric
lines. Length 14 mm.; height 11 mm.

Affinities —This species is more inflated, the anterior part is more rounded,
and the concentric ribs are stronger than in C. pulchra (Sowerby).

T'ype-—From the Gault of the Perte-du-Rhone.

Distribution.—Lower Gault of Folkestone.

1 See, for example, Stoliczka, ‘Cret. Fauna 8. India,’ vol. ii (1870), pl. ii, figs. 10, 11 ; Moesch,
‘Mon. Pholadomyen’ (1874), pl. xxxv, fig. 5; Geinitz, ‘Das Elbthalgeb. in Sachsen’ (‘ Palewonto-
graphica,’ vol. xx, pt. 2, 1873), pl. xix, figs. 6,7; Weller, ‘Cret. Pal. New Jersey,’ vol. iv (1907),
pl. lviii, figs. 3—9.

2 E.g. P. subdinensis (d’Orbigny), ‘Pal. Frane. Terr. Crét.,’ vol. iii (1844), p. 38, pl. cel, figs.
1—3, and ‘ Prodr. de Pal.,’ vol. ii (1850), p. 157.

260 CRETACEOUS LAMELLIBRANCHIA.

Cusptpanta uNDuULATA (Sowerby), 1827. Plate XLIV, fig. 4.

1827. Nucuna unpvuxara, J. de C. Sowerby. Min. Conch., vol. vi, p. 104, pl. dliv,

fig. 3.
1854. Neara ? — J. Morris. Cat. Brit. Foss., ed. 2, p. 216.
1866. -- -- F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Mater. Pal. Suisse, ser. 4), p. 421.
1871. a — F. Stolickza. Paleont. Indica, Cret. Fauna S. India,

vol. il, p. 322.

Remarks.—A few specimens resembling Sowerby’s figure of C. undulata have
been found. They appear to differ from C. Sabaudiana only in the less oblique
form of the shell and the more convex postero-ventral margin. More specimens
are needed in order to determine whether C. Sabaudiana and C. undulata are really
distinct or only varieties of one species.

Type.—The type was preserved in pyrites, and came from Folkestone; it was
formerly in the British Museum, but has now perished.

Distribution.— Gault of Folkestone.

CuspmpartaA puLcHRA (Sowerby), 1850. Plate XLIV, figs. 5, 6.

1850. Lepa puncura, J. de C. Sowerby in F. Dixon. Geol. Sussex, p. 346 (p. 382,
ed. 2), pl. xxviii, fig. 10.
1854. — PP — J. Morris. Cat. Brit. Foss., ed. 2, p. 205.
1897. Cusprparta caupara, H. Woods. Quart. Journ. Geol. Soc., vol. liii, p. 393,
pl. xxvii, figs. 19, 20.

Description—Shell convex, with the posterior and antero-dorsal parts com-
pressed; sub-triangular, oblique, somewhat inequilateral, highest in front of the
umbones. Dorsal margin nearly straight. Anterior margin shghtly convex.
Antero-ventral margin rounded. Ventral margin curving upwards and passing
gradually into the posterior margin, which forms an acute angle with the postero-
dorsal margin. Umbones pointed, curved inwards and slghtly backwards.
Ornamentation consists of regular, concentric ribs which become indistinct on the
antero-dorsal and postero-dorsal parts.

Measurements :

(1) (2)
Length ; ; : 27 : 22 mm.
Height 3 : 5 19 3 (1:5) Be
Thickness , 14. ; 1 ee

(1,2) Upper Chalk, Norwich.

Palxontographical Society, 1910.

Bee vMEOUN OG by AGr iE

CRETACKOUS LAMELLIBRANCHIA

ENGLAND.
HENRY WOODS, M.A.

VOL. If. PART VIL
INOCERAMUS.

Paces 26]—284; Piares XLV—L.

LONDON:
PRINTED FOR THE PALHZONTOGRAPHICAL SOCIETY

JANUARY, 1911.

PRINTED BY ADLARD AND SON, LONDON AND DORKING.

CUSPIDARIA. 26]

Affinities —When describing the Mollusca of the Chalk Rock in 1897 only an
imperfect specimen of C. pulchra was available for study, and | identified it with
C. caudata (Nilsson). ‘lwo better specimens from Norwich have now been seen,
and anew figure of Nilsson’s type has been published by Hennig.’ The English
form—figured by Sowerby as Leda pulchra—differs from the type of C. cauwdata in the
relatively greater height of the anterior part of the shell, the more nearly posterior
position of the umbones, and in the posterior rostrum proceeding from the level
of the hinge-line instead of below it. C. pulehra approaches closely the specimen
figured by Goldfuss* as C. caudata, and it was chiefly on account of this resem-
blance that I identified the English form with Nilsson’s species. Stoliczka® and
Hennig, however, consider that Goldfuss’ specimen is not an example of C. caudata.
If all the specimens figured by foreign writers as C. caudata really belong to that
species then it is obviously extremely variable and might well include C. pulehra.
Without an opportunity of studying a series of foreign specimens and a larger
number of English examples it seems, at present, preferable to regard C. pulchra
as distinct from C.caudata. None of the English specimens shows evidence of the
existence of such a long posterior beak as is present in the type of C. caudata,

A specimen of Cuspidaria from the Upper Greensand of Devizes (Plate XLIV,
fic. 7) resembles some specimens of C. pulchra and may be provisionally referred
to that species.

T'ype.—The type, from the “ Chalk of Kent,” cannot now be found.

Distribution —Chalk Rock of Cuckhamsley, Berkshire, and Henley Park.
Upper Chalk (zone of Belemnitella mucronata) of St. Giles’ Gate and Horstead,
near Norwich.

1 ‘Revis. Lamellibr. i Nilsson’s Petrific. Suecana Format. Cret.’ (1897), p. 62, pl. ili, fig. 28;
Rayn, ‘ Mollusk. i Danmarks Kridtafl. I. Lamellibr.’ (1902), p. 65 [1383], pl. iv, fig. 24.
2 « Petref. Germ.,’ vol. ii (1840), p. 251, pl. eli, tig. 17. Compare also Wollemann, ‘Senons v.
Biewende’ (‘Jahrb. d. k. preuss. geol. Landesanst.,’ fiir 1900), p. 23, fig. 5; Miiller, *‘ Mollusk. d.
Untersen. v. Braunschweig u. Isede’ (1898), p. 77, pl. x, figs. 10,11; Wollemann, ‘Fauna der Line-
burg. Kreide’ (1902), p. 80.

3 *Paleont. Indica, Cret. Fauna S. India,’ vol. i (1870), p. 41.

262 CRETACEOUS LAMELLIBRANCHIA.

Family —PERNIDA, Zittel.

(Continued from page 95.)

Genus—Inoceramus, J. Sowerby,! 1819.

(J. Parkinson [ex Sowerby MS.], ‘Trans. Geol. Soc.,’ ser. 1, vol. v, 1819, p. 55. J. Sowerby,
‘Trans. Linn. Soc.,’ vol. xiii, 1822, p. 455.)
Tyoceramus Neocomtmnsts, d’Orbiguy, 1846. Plate XLV, figs. 1, 2.

1846. Inoceramus NeEocomreysts, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. ii,

p. 503, pl. eecciii, figs. 1, 2.

1850. — — d’Orbigny. Prod. de Pal., vol. 11, p. 83.

1854. - - J. Morris. Cut. Brit. Foss., ed. 2, p. 170.
1855. ==: G. Cotteau. Moll. Foss. de ’Yonne, p. 107.
1869. . ~- F.J, Pictet and G. Campiche. Foss. Terr. Crét.

Ste. Croix (Matér. Pal.
Suisse, ser. 5), p. 104.
1900. — A. Wollemann. Die Bivalv. u. Gastrop. d.
deutsch. u. hollind.

Neocoms, p. 60.
? 1905. - EH. Harbort. Die Fauna d. Schaumburg-
Lippe’schen Kreidemulde,

p. 44, pl. ix, figs. 4-6.

Description.—Shell inequivalve, very inequilateral, a little higher than long.
Valves convex, with flattened sides, and the posterior part compressed. Anterior
margin nearly straight; posterior and ventral margins rounded. Posterior
margin forming an obtuse angle with the hinge-line. Anterior part nearly
perpendicular to the plane of the valves and excavated near the umbones.
Umbones terminal, curved inwards and forwards. Hinge-line equal to more than
half the height of the shell, and making an angle of about 100° with the anterior
margin.

Ornamentation consists of narrow, regular, concentric ribs with an unsym-
metrical curvature ; the interspaces are broad and regularly concave.

'Tn rearranging the collection of Inocerami in the British Museum, Mr. R. B. Newton and Mr.
C. D. Sherborn have found several type-specimens, the existence of which had not been previously
recognised ; this discovery has greatly facilitated my work. I am also indebted to Mr. Newton and
Mr. Sherborn for assistance in selecting specimens for figuring. I wish to thank Mr. C. P. Chatwin
for information respecting the zonal distribution of the species of Inoceramus in the Chalk and for

other assistance. Dr. Blackmore, Dr. Rowe, and Mr. G. E. Dibley have helped by the loan of
numerous specimens from their collections.

INOCERAMUS. 263

Affinities—See I. anglicus (p. 264).

I. neocomiensis appears to be allied to J. Hwaldi, Schliiter,! of which only one
figure has yet been published. he differences seen are in the greater relative
height, the more inequilateral form, and the greater convexity of the curve of the
ribs of I. neocomiensis.?

Remarks.—This species was first recorded in England by Fitton. Only a few
specimens have been seen; they agree fairly well with d’Orbieny’s figure, but the
ribs appear to be better defined, and usually the posterior ear-like part is less
distinctly limited. The English specimens are not sufficient to show whether the
inequality of the valves is as great as in d’Orbigny’s figure.

T'ype.— Prof. Boule informs me that d’Orbigny’s figures are restorations based
on two specimens from the Barremian of Bettancourt. The types are in the
Natural History Museum, Paris.

Distribution.—Lower Greensand (Fitton’s Bed 15) of Atherfield. Hythe Beds
of Lympne. Lower Greensand of Nutfield.

TNoceraMus, sp.

A few specimens of Inoceraimus, not sufficiently perfect for description, have
been found in the Speeton Clay (zone of Pelemnites lateralis) and in the Spilsby
Sandstone of Holton and Acre House.

Inoceramus Satomont, @Orbigny, 1850. Plate XLV, figs. 83—7.

1850. Inocrramus Satomont, A. d’Orbigny. Prodr. de Pal., vol. 1, p. 139.
1853. — -—- FJ. Pictet and W. Roux. Moll. Foss. Grés verts
de Gentve, p. 501,

pl. xhi, fig. 3.

5. — — G. Cotteau. Moll. Foss. de ?Yonne, p. 107.

1869. _ — F. J. Pictet and G. Campiche. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse,
ser. 5), p. 109, pl. elx, figs.
5—8.

Description.— Left valve inflated, subquadrate, very inequilateral. Length and
height nearly equal. Anterior half of valve very convex ; posterior half compressed.
Anterior end of valve more or less nearly perpendicular to the plane between the
valves, and concave near the umbo. Umbo anterior, prominent, pointed, incurved.

1 See footnote on p. 267.

2 Compare also forms described by Schmidt as allied to I. neocomiensis, ‘Mém. Acad. Imp. Sci.
St. Pétersb.,’ ser. 7, vol. xviii (1872), pp. 155—161, pl. ii, fig. 8, pl. iii, figs. 6—9.

264, CRETACEOUS LAMELLIBRANCHIA.

A broad, usually shallow suleus extends from below the umbo to the ventral margin,
where it produces a slight sinuosity ; usually the sulcus starts at some distance from
the umbo, and may consequently be absent in small specimens. Ornamentation
consists of small, narrow, somewhat irregular concentric ribs, separated by broad,
shallow, concave interspaces.

Affinities—This species is related to I. concentricus, Parkinson, but is dis-
tinguished by its subquadrate outline, by the length and height being nearly equal,
and by the presence of the suleus.

Remarks.—All the specimens seen are internal casts of left valves. The
examples figured by Pictet and Roux and by Pictet and Campiche are also left
valves.

T'ype.—D’ Orbigny’s specimens came from the Albian of Novion, Clar, Géraudot,
and Saint Florentin.

Distribution.— Mammillatus bed of Copt Point, Folkestone.

INOCERAMUS ANGLICUS, sp. nov. Plate XLV, figs. 8—10. Text-fig. 29.

1822. InocEramus, sp., G. Mantell. Foss. 8. Downs, p. 96, pl. xix, fig. 20.

1859. -- Crispi, I. Wiltshire. The Red Chalk of England (Geol.
Assoc.), p. 16, pl. i, fig. 4.
1875. : concenrricus, A. J. Jukes-Browne. Quart. Journ. Geol. Soc.,

vol. xxxi, p. 299.

Description.—Shell equivalve or nearly equivalve, very inequilateral. Anterior
part of shell convex, the convexity decreasing with age; posterior part com-
pressed, flattened. Anterior slope of valves steep. Anterior margin moderately
convex ; ventral margin very convex; posterior margin curved, and forming an
obtuse angle with the hinge-line. Length of hinge equal to rather more than a
third of the height of the shell. Umbones nearly terminal, with a small anterior
curvature.

Ornamentation consists of strong, regular, concentric ribs, which have a sub-
symmetrical curvature, and become less distinct on the posterior flattened part of
the shell. The ribs have rounded summits, and are separated by broad rounded
furrows with symmetrical slopes. Some of the ribs bifurcate, some may be dis-
continuous, or new ribs may be intercalated.

Affinities. —The equal size of the valves, the greater convexity of the curve of
the ribs, the convex form of the anterior margin, and the outward slope of the
anterior part of the valves distinguish this species from J. neocomiensis, d’Orbigny

(p. 262).

INOCERAMUS. 265

I. anglicus also resembles I. Hwaldi, Schliiter,' but is relatively higher, more
inequilateral, and the ribs are more strongly curved.

Remarks.—This species has been usually identified as I. concentricus, Parkinson,
but the equal size of the valves and other characters readily distinguish it from

Fia. 29.—Inoceramus anglicus, sp. nov. Red Limestone, Hunstanton. Sedgwick Museum,
Cambridge. Part of right valve. Natural size.
that species. An example from Hunstanton was fi
(= Crippsi), Mantell.
Distribution.—Red Limestone of Hunstanton. Gault of Folkestone. Cam-
bridge Greensand (derived from the Gault). Marl in the Gault of Roydon, West
Norfolk. Upper Greensand of Haldon, the Isle of Wight, and Devizes.

eured by Wiltshire as [. Crispii

=

Inoceramus concentricus, Parkinson, 1819. Plate XLV, fig. 11; Plate XLVI,
fies. 1—10; Plate XLVII, figs. 1, 2.

1819. Inocreramus concentricus, J. Parkinson. Trans. Geol. Soc., ser. 1, vol. v,
p- 58, pl. i, fig. 4.

1821. — — J. Sowerby. Min. Conch., vol. iii, p. 183, pl.
cecy, figs. 1—6.
1822. —_— -- G. Mantell. Foss. S. Downs, p. 95, pl. xix,

figs. 15, 19.
= — — A, Brongniart in Cuvier. Ossemens Foss.,
vol. ii, pt. 2, pp. 333, 336)
609, pl. vi, fig. 11.
1828. _ arypHmorpes, J. de C. Sowerby. Min. Couch, vol. vi, p. 161,
pl. dlxxxiv, fig. 1.

1 See footnote on p. 267.

266

1906.

Non 1837.

CRETACEOUS LAMELLIBRANCHIA.

Catiuivus pyrirormis, H. Michelin. Magasin de Zoologie, iii, Classe 5, pl.
XXX.
[Iyocrramus concentricus, A. Goldfuss. Petref. Germ., vol. 11, p. 111,
pl. cix, figs. 8a, b, ec, (non
8d, e, f).
— - P. Matheron. Catal. Foss. des Bouches-du-
Rhone, p 173.
A. dOrbigny. Pal. Franc. Terr. Crét., vol. ii,
p. 506, pl. eecciv.
— A. Leymerie. Statist. geol et min. de l’Aube,
Atlas, pl. v, fig. 12.
-— H. B. Geinitz. Das Quadersandst. oder Kreide-
geb, in Deutschland, p. 174.
— A. dOrbigny. Prodr. de Pal., vol. ii, p. 138.
--- — F. J. Pictet and W. Roux. Moll. Foss. Gris
verts de Geneve, p. 500,
pl. xl, fig. 2.
— -- J. Morris. Cat. Brit. Foss., ed. 2, p. 169.
- GrypHmorpeEs, J. Morris. Tbid., p. 169.
concentricus, G. Cotteau. Moll. Foss. de l’Yonne, p. 107.
— I’. J. Pictet and G. Campiche. Terr. Crét. Ste.
Croix (Mater. Pal. Suisse,
ser. 5), p. 107.
- - J. F. Whiteaves. Mesozoic Fossils (Geol. Surv.
Canada), vol. i, pp. 79, 241.
— C. Schliiter. Palseontographica, vol. xxiv, p.
255;
_ — G. Bihm. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxix, p. 288.
-— Rk. B. Newton. Proce. Dorset Nat. Hist. and
Antiq. Field Club, vol. xviii,
p. 88, pl. iii, fig. 12.
A, Wollemann. Jahrb. d. k. preuss. geol.
Landesanst. fiir 1906, vol.
xxvii, p. 271.

- G. Fischer de Waldheim. Oryctogr. de Mos-
cou, p. 177, pl. xx, figs. 1—8.
(= Aucella Keyserlingiana,
Trautschold).
F. A. Rimer. Die Verstein d. nord-deutsch.
Kreidegeb., p. 61.
FE. Forbes. Quart. Journ. Geol. Soe., vol. i,
p. 247 (I. neocomiensis, d’Orb.)
-- -- A. I]. Reuss. Die Verstein. der bohm. Kreide-
format., pt. 2, p. 24.
— — J. Miller. Petref. der Aachen. Kreidef., pt. 1,
p- 30.

[INOCERAMUS. 267

Non 1875. Inoceramus concenrricus, A. J. Jukes-Browne. Quart. Journ. Geol. Soe.,

vol. xxxi, p. 299.

Description.—Shell more or less ovate, much higher than long, very inequi-
lateral and inequivalve. Anterior part of valves flattened or coneave, often more
or less nearly perpendicular to the plane between the valves. Posterior part of
the valves somewhat expanded and less convex than the part below the umbones.
Postero-dorsal part forming a small wing. Left valve very convex, with a high,
narrow, pointed, terminal umbo which is considerably incurved and bends forwards.
Right valve considerably less convex than the left valve, with a small, terminal
umbo curved forwards but only shghtly inwards. Hinge-line less than half the
height of the shell.

When the shell is perfect the surface is nearly smooth except for numerous
regular growth-rings. When the outer layer of the shell is wanting concentric
undulations or ribs having an unsymmetrical curvature are seen, and are separated
by concave furrows.

Affinities.—JL. concentricus has been compared by Wollemann with J. Hivaldi,
Schliiter,’ but the prominent umbo and other characters readily distinguish it from
that species. See also /. concentricus var. subsulcatus, and I. sulcatus (below).

Remarks.—Whilst the left valve in the specimens from the Blackdown Greensand
agrees closely with that of specimens found in the Gault, the right valve in many
(but not all) cases is relatively more convex, especially between the umbo and the
postero-ventral extremity, and the ribs are more sharply curved. A similar
modification is seen in the examples from the Red Limestone of Hunstanton. There
seems no reason for regarding the specimens with these characters as forming
more than a local variety dependent on the fact that they lived under conditions
different from those which prevailed where the Gault was deposited.

I. gryphevides, Sowerby, was founded on an internal cast of J. concentricus
from the Upper Greensand; in such casts the ribs are more prominent than on
the surface of the shell itself.

All the examples from the Cambridge Greensand which have been recorded as
I. concentricus appear to belong to J. anglicus (p. 264).

Types—The type, which came from the Gault of Folkestone, cannot now be
found. The specimens from the same locality figured by Sowerby and by Mantell,
and the type of J. gryphexoides from the Upper Greensand near Lyme Regis, are in
the British Museum.

Distribution.—In all zones of the Gault of Folkestone. Gault of Aylesford,

1 *Monatsber. d. k. preuss. Akad. Wissensch., Berlin’ (1860), p. 345. Schliiter, * Palewonto-
graphica,” vol. xxiv (1877), p. 255. Wollemann, “ Bivaly. u. Gastrop. d. norddeutsch. Gaults”

(‘ Jahrb. d. k. preuss. geol. Landesanst.,’ vol. xxvii, 1906), p. 272, pl. vi, fig. 9.

268 CRETACEOUS LAMELLIBRANCHIA.

Dunton Green (Kent), Black Ven, and Okeford Fitzpaine. Upper Greensand
(zone of Schlanbachia rostrata) of Blackdown, Sidmouth, Lyme Regis, and Potterne
near Devizes. Limestone in the Gault of West Bilney, Roydon, and Grimston
(West Norfolk). Red Limestone of Hunstanton.

INOCERAMUS CONCENTRICUS var. suBsULCATUS, Wiltshire, 1869. Plate XLVII, figs.
3—14.
1853. Inoceramus sutcatus, F. J. Pictet and W. Roux. Moll. Foss. Gres verts

de Gentve, p. 499, pl.
xlii, figs. 1 d, e, f.

1869. sussuLecatus, 7’. Wiltshire. Quart. Journ. Geol. Soc., vol. xxv,
pp. 188, 190.
1879. -— = F. G. H. Price. The Gault, p. 54.

In the lowest zone of the Upper Gault there occur forms of Inoceranus which
differ from I. concentricus only in the fact that radial plications are more or less
extensively developed. In these forms every stage can be traced between J. con-
centricus without plications into forms in which the phcations are almost as
complete as in I. sulcatus. A specimen, which differs from I. concentricus only in
the occurrence of one shallow plication, is shown in fig. 3 (Plate XLVII); others
are similar, but possess two or three plications (Plate XLVI, figs. 4,5). In most
cases the early part of the shell agrees entirely with J. concentricus; but the
duration of this stage varies considerably in different individuals, and sooner or
later either a few or many plications are developed. When the plications are
numerous and start from near the umbo the shell closely resembles I. sulcatus,
but may usually be distinguished by the rounded (instead of angular) form of
the plications, and by the presence of concentric ribs. For these forms, which
characterise a definite horizon in the Gault, it will be convenient to adopt as a
varietal designation the name subsulcatus, given by Wiltshire in 1869.

From a study of many forms of this variety it seems evident that J. sulcatus
has been derived from J. concentricus by the gradual development of plications, and
this view is in accordance with stratigraphical distribution, since J. concentricus is
the earlier of the two species, being found throughout the Gault, whilst [. sulcatus
occurs in the upper part of the Gault only.

If J. sulcatus has been derived from J. concentricus, then it is clearly more
nearly related to that than to any other species of Znoceramus, and cannot therefore
be placed in a separate genus or sub-genus (Actinoceramus), as was proposed by
Meek.’ Further, in the early stages of the variety subsulcatus the shell is a typical

1 «Check List Cret. Foss. N. Amer.’ (‘Smithson. Miscell. Coll.,’ No. 177, 1864), p. 32. Stoliezka,
‘Cret. Fauna 8. India,’ vol. ui (1871), p. 393. Meek and Hayden, ‘Invert. Cret. Tert. Foss. U.
Missouri’ (1876), p. 39.

INOCERAMUS. 269

Inoceramus, but subsequently it possesses the characters of Actinoceramus. Also
it appears that a somewhat similar plication has originated independently in J.
Salomoni (p. 263), and probably too in J. radians, Schliiter,' and I. fasciatus, Miller.’

Pictet and Roux regarded subsulcatus as a variety of I. sulcatus im which the
number of plications had decreased ; the stratigraphical distribution and also the
evidence of the extensive series of specimens of subsulcatus which has now been
obtained are opposed to this view.

Distribution.— Lowest zone of the Upper Gault of Folkestone. Upper Green-
sand of Blackdown. Red Limestone of Hunstanton.

Inoceramus sutcarus, Parkinson, 1819. Plate XLVII, figs. 15—20.

1819. Inoceramus suucatvs, J. Parkinson. Trans. Geol. Soc., ser. 1, vol. v, p. 59,
pl. i, fig. 5.

1821. — - J. Sowerby. Min. Conch., vol. iii, p. 184, pl. ecevi,
figs. 1—7,
1822. — — G, Mantell. Foss. 8. Downs, p. 95, pl. xix, fig. 16.

= — A. Brongniart in Cuvier. Ossemens Foss., vol. ii,
pt. ii, pp. 333, 336, pl. vi, fig. 12.

1836. — A, Goldfuss. Petref. Germ., vol. ii, p. 112, pl. ex,
fig. 1.

1837. ~ W. Hisinger. Lethea Suecica, p. 56, pl. xvii, fig. 9.

1846. : — A. Wd Orbigny. Pal. Franc. Terr. Cret., vol. iii, p. 504,
pl. ececiil, figs. 5—5.

1850. —- — A.dOrbigny. Prodr. de Pal., vol. ii, p. 139.

1853. — — F.J. Pictet and W. Roux. Moll. Foss. Gres verts de

Gentve, p. 499, pl. xlii,
figs. la-c (not d-f).

1854. — — J.Morriz. Cat. Brit. Foss., ed. 2, p. 170.
1855. -- — G. Cotteau. Moll. Foss. de lYonne, p. 107.

1864. Acrinoceramus suucatus, I’. B. Meek. Check List Cret. Foss. N. Amer.
(Smithson. Miscell. Coll., No.
177), p. 32.
1869. [noceramvus sutcatus, F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal. Suisse,
ser. 5), p. 105.
1875. — — A. J. Jukes-Browne. Quart. Journ. Geol. Soc., vol.
xxxi, p. 298,
C. Schliiter. Palwontographica, vol. xxiv, p. 256.
1884. “= (Acrinoceramus) sutcatus, J. F. Whiteaves. Mesozoic
Fossils, vol. i (Geol. Surv.
Canada), p. 241, pl. xxxii,
fig. 3.

1 « Paleontographica,’ vol. xxiv (1877), p. 270, pl. iii, fig. 2.
2 ‘Jahrb. d. k. preuss. geol. Landesanst. fiir’ 1887 (1888), p. 416, pl. xviii, fig. 3.

or
ob

bo
~I
oS

CRETACEOUS LAMELLIBRANCHIA.

1906. Inoceramus sutcatus, A. Wollemann. Jahrb. d.k. preuss. geol. Landesanst.
fiir 1906, vol. xxvii, p. 273, pl. vi,
fig. 10.

Non 1827. — — 8. Nilsson. Petrif. Suecana, p. 18.

Description.—Shell more or less ovate, much higher than long, very inequi-
lateral, more or less considerably inequivalve. Anterior part of valves flattened

Fig. 30.—Inoceramus, sp. Gault, Folkestone. Sedgwick Museum, Cambridge. Internal cast of right
valve. x 4.

or concave. Posterior part somewhat expanded and less convex than the part
below the umbones. Left valve very convex, with a high, narrow, pointed
anterior umbo which is considerably incurved and bends forwards. Right valve
rather less convex than the left valve, with a smaller umbo which bends forwards
and slightly inwards.

Ornamentation consists of strong angular radial ridges (plications), usually
from eight to ten on each valve, which are often unequal in size and are separated

i

INOCERAMUS. 271

by deep furrows. The ridges are often at unequal distances from one another;
some of them start from the umbo, others may be intercalated or may arise by
bifurcation. Fine concentric hnes cover the shell and are folded where they
cross the ridges and furrows.

Affinities— Although the radial plications give a distinctive appearance to this
species, yet the form of the shell closely resembles that of I. concentricus, the main
difference being that in the former the difference in the convexity of the two valves
is usually less marked than in the latter.

T'ypes.—The type, from the Gault of Folkestone, is in the British Museum.
The specimens from near Lewes, Folkestone (except figs. 1 and 2), and Clophill
figured by Sowerby, and the specimens figured by Mantell are in the British
Museum.

Distribution.—Gault of Folkestone, Aylesford, Ringmer, Eastbourne, the Isle
of Wight, and Leighton Buzzard. Upper Greensand (zone of Schlanbachia
rostrata) of Blackdown, Sidmouth, Black Ven, and Lulworth. Red Limestone of
Hunstanton, South Willingham (Lincolnshire), and Speeton.

Ivoceramus, sp. Text-fig. 30.

Specimens of a large, slightly convex Inoceramus are found in the Gault
of Folkestone and the Upper Greensand of Potterne (Devizes) and the Isle
of Wight, but are not sufficiently perfect for determination. The umbones are
terminal, and the hinge-line is nearly at right angles to the anterior margin. The
anterior parts of the valves slope steeply to the margin. Small and rather
distant concentric ribs are present. This form shows some resemblance to I. pictus
(p. 279), but is less convex, and possesses fewer ribs.

Inoceramus tenuis, Mantel/, 1822. Plate XLVIII, fig. 1. Text-figs. 31, 32.

1822. Inocrramvus tenuis, G. Mantell. Foss. 8. Downs, p. 182.
1854. ~- — J.Morris. Cat. Brit. Foss., ed. 2, p. 170.
? 1859. -- — T. Wiltshire. Red Chalk ‘of England (Geol. Assoc.),
p- 16, pl. i, fig. 5.
1866. Prrwna rissa, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. xvii, p. 178.

Non 1841. Inoceramus tenuis? F. A. Rimer. Die Verstein. d. nord-deutsch.
Kreidegeb., p. 62, pl. viii,

fig. 11.

Description.—Shell inequivalye, very inequilateral, convex ; postero-dorsal

part compressed ; antero-dorsal part excavated and more or less nearly perpen-

272 CRETACEOUS LAMELLIBRANCHIA.

dicular to the plane of the valves; height greater than length. Hinge-line equal
to about two-thirds of the height of the shell. Ventral margin very convex ;
posterior margin forming an obtuse angle with the hinge-line. Umbones terminal,
curved inwards and forwards, the left umbo larger and more prominent than the
right. Surface smooth, except for growth-rings.

Affinities. —I. tenuis resembles I. concentricus, but the left umbo is less

‘

Bp ;

Fia. 31.—Inoceramus tenwis, Mantell. Chalk Marl, Hamsey. The type, No. 5890, British Museum (Nat.
Hist.). ‘The specimen is somewhat compressed from front to back. Left valve and anterior view of both
valves. Right valve shown in the next figure.

prominent, the length of the shell is relatively greater, and the concentric rings
are less prominent.

The fragmentary specimens described by Seeley as Peria lissa appear to belong
to this species.’

Types.—In the British Museum (No. 5890) from the Chalk Marl of Hamsey.
A fragment, from the Red Limestone of Hunstanton, which appears to be one of

1 The form from the Red Limestone of Hunstanton which was named Perna transversa by Seeley
is at present known only by an imperfect left valve. It is perhaps allied to I. tenuis, but is remark-
able in being much longer than high. The type is in the Sedgwick Museum, Cambridge. Seeley,
‘Ann. Mag. Nat. Hist.,’ ser. 3, vol. xvii (1866), p. 179.

INOCERAMUS. 273

the specimens on which Seeley’s description of Perna lissa was based, is in the
Sedewick Museum, Cambridge.

Fig. 32.—Inoceramus tenuis, Mantell. Right valve. See Fig. 31.

Distribution.—Red Limestone of Hunstanton, Louth, and Speeton. Upper

Greensand of Ventnor and Potterne. Chalk Marl of Hamsey.

> ied
oO).

InocerAmus: Cerrrrsi, Mantell, 1822. Plate XLVIII, figs. 2,5. Text-figs. 33

Foss. S. Downs, p. 133, pl. xxvii, fig. 11.

Petref. Germ., vol. ii, p. 117, pl. exii,
fiz. 5 (non Mantell).

A.dOrbigny. Pal. France, Terr. Crét., vol. iii, p. 515,

1822. Inoceramus Cripsu, G. Mantell.
1836. — LAtus, A. Golidfuss.

1846.

pl. eccevill, figs. 12.
1854. — Crispi, J, Morris. Cat. Brit. Foss., ed. 2, p. 169.
1904. — Latus, E. T. Newton and A. J. Jukes-Browne. In Jukes-
Browne, Cret. Rocks of Britain,
vol. iii, p- 449.
1909. Crrrpst, J. Bihm. Subhereyn. Kreidemulde (Abhandl. d. k.

preuss. geol. Landesanst., N.F., 56),

p. 41, pl. ix, fig. 1.

i)

CRETACEOUS LAMELLIBRANCHIA.

Non 1822. Inoceramus uarus, G. Mantell, Foss 8. Downs, p. 216, pl. xxvii, fig. 10.

— 1828. — — J. de C. Sowerby. Min. Conch., vol. vi, p. 159, pl.
d)xxxii, fig. 1.
1836. -- Crispu, A. Goldfuss. Petref. Germ, vol. ii, p. 116, pl. exii, fig. 4.
1840. — — 4H. B. Geinitz. Char. d.Schicht. u. Petref. des siichs.
Kreidegeb., pt. 1, p. 27.
1841. -- Latus, I’. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
paole:
a — Cripsu, Rimer. Ibid., p. 63.
— 1846. = — H. B. Geinitz. Grundr. d. Verstein., p. 464.

— : LATUS, Geinitz. Ibid., p. 463.
= — A. HE. Reuss. Die Verstein. der béhm. Kreideformat.,
pt. 2, p. 25.
~ — Cripsu, Tteuss. Ibid., p. 25, pl. xxxvii, figs. 10, 12.

— 1847. - — J. Miiller. Petref. der Aachen. Kreidef., pt. 1, p. 30.
— 1852. — — F. Rémer. Kreidebild. v. Texas, p. 56, pl. vii, fig. 2.
— — — Latus, Rimer. Ibid., p. 60.
1859. -- Crispi, 7’. Wiltshire. Red Chalk of England (Geol. Assoc.),
p- 16, pl. i, fig. 4.
- 1868. — Cripst, A. v. Stronbeck. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xv, p. 152.
1866. --- — K.A. Zittel. Bivalv. d. Gosaugeb., ii (Denkschr, d. k.

Akad. Wissensch , Wien, Math.-nat.
Cl., vol. xxv), p. 95, pl. xiv, figs. 1—5,
pl. xv, figs. 1—5.

— - tatus, Zittel. Ibid., p. 100, pl. xiii, fig. 7.

1869. — Cripst, E. Favre. Moll. Foss. de la Craie de Lemberg, p. 132.
— 1870. — Latus, I’. Rimer. Geol. Obersehles., p. 316, pl. xxxiv, fig. 12.
—- — -- Criesit, Rimer. Ibid., p. 356, pl. xxxix, fig. 9.

1871. — Crispranus, I’. Stoliczka. Paleont. Indica, Cret. Fauna

8. India, p. 405, pl. xxvii, figs.
1—3, pl. xxviii, fig. 2 (not pl.
xxvil, fiz. 3, I. Heberti, Fallot).
1872. ~~ Cripst, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal-
wontographica, vol. xx, pt. 2),
p. 49, pl. xiii, figs. 11-15.
—— — Latus, Geinitz. Ibid., p. 45, pl. xiii, figs. 4, 5.
1873. a — Geinitz. Neues Jahrb. fiir Min., ete., p. 11.

— -— Cripst, Geinitz. Tbid., p. 16.
1875. — uatus, C. Décocg. Assoc. Franc. Avane. Sci. (Lille), p. 369.
1876. — Crips, D. Brauns. Zeitschr. f. d. gesammt. Naturwissenseb.,

vol. xlvi, p. 378.
-—— — — = ry var. Barapini, F. B. Meek. Invert. Cret. Tert.
Foss. U. Missouri, p. 49, pl. xii, fig. 3, pl. xiii, fig. 1.
—- - P var. suBuNDaTUS, I’. B. Meek. Bull. U.S. Geol. and
Geogr. Surv. Territories, vol. ii, p. 358, pl. iii,
figs. 1, 3.

Non 1877.
— 1878.

— 1879:

— 1694:

— 1903.

INOCERAMUS. 275

Ivoceramus Crist, C. Schliiter. Palwontographica, vol. xxiy, p- 277.
= Latus, C. Barrois. Ann. Soc. géol. Nord, vol. vy, pp. 407
475.
— Cxrpsi, vars. PROXIMUS, SUCIENSIS, Barasrnt, J. F. Whiteaves.
Mesozoic Foss., vol. i (Geol. Surv.
Canada), pp. 172—174.
— — 4H. Schrider. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxxiv, p. 273.
— Crrest, FE. Fallot. Ann. Sci. géol., vol. xviii, p. 250.
== Cripsur, A. Peron. Hist. Terr. Craie S.E. du Bassin Anglo-
Parisien, p. 158,
— — G. Miiller. Jahrb. d. k. preuss. geol. Landesaunst. fiir
1887, p. 416.
— — E. Holzapfel. Die Mollusk. Aachen. Kreide (Paleon-
tographiea, vol. XXXV), p. 222.
-— Cries, A. Fritsch. Stud. im Gebiete der béhm. Kreide-
format., iv, Teplitz. Schicht., p- 82, fig. 73.
-- — 0. Griepenkerl. Senon. vy. Konigslutter (Paleont.
Abhandl., vol. iv), p. 50,
— Criprsu, J. Béhm. Palwontographica, vol. xxxviii, p. 81.
— — K. Futterer. Ober. Kreidebild. St. Croce (Palaont.
AbhandL., vol. vi), p. 80.
= Cripsi, EB. Stolley. Kreide Schleswig-Holsteins (Mittheil.
Min. Instit. Universit. Kiel, vol. t)}-
p-. 241.
-- Crippst, B. Lundgren. Mammilatus och Mucronata zonerna
(K. Svenska Vet.-Akad. Hundl.,
N.F., vol. xxvi, No. 6), p- 45.
— Cripsu, R. Leonhard. Palwontographieca, vol. xliv, p. 49.
-— Latus, Leonhard. Ibid., p. 49.
-— Crips, G. Miiller. Mollusk. Untersen. vy. Braunschweig u.
Ilsede (Abhandl. d. k. preuss. geol.
Landesanst., n.¥., 25), p. 45, fig. 12.
— — G. de Alessandri. Paleont. Ital., vol. iv, p. 194, pl.
xvi, fig. 9.
-— Latus, Alessandri. Ibid., p. 196.
— Criesi, A. Wollemann. Jahrb. d. k. preuss. geol. Landesanst.
fiir 1900, vol. xxi, p. 18.
— Latus, F. Sturm. Ibid., vol. xxi, p. 93, pl. x, fig. 2.
— Cripst, H. Imkeller. Paleontographica, vol. xlviii, p- 33.
-- — var. RApIosA, A. Quaas. Ibid., vol. xxx, 2, p. 170,
pl. xx, figs. 9, 10.
= — A. Wollemann. Luneburg. Kreide (Abhandl. d. k.
preuss. geol. Landesanst., N-P.,
37), p. 72.
— Larus, W. Petrascheck. Jahrb. d. k. k. geol. Reichsanst., vol. liii,
p. 165.

,

276 CRETACEOUS LAMELLIBRANCHIA.

Non 1905. Inoceramus Cripst, 7. Wegner. Zeitschr. d. deutsch. geol. Gesellsch.,
HT] g
vol. lvii, p. 161.

— 1906. _- Crispranus, J. Pethié. Paleontographica, vol. li, p. 232.
— 1908. -- Criesu, A. Stojanoff. Aun. géol. min. Russie, vol. x, p. 121.

Deseription.—Shell thin, equivalve, moderately inequilateral, convex between
the umbo and the ventral margin ; postero-dorsal part compressed and flattened ;
antero-dorsal marginal part nearly perpendicular to the plane of the valves and

Fia. 33.

Fia.33.—Inoceramus Crippsi, Mantell. The type, British Museum (Nat. Hist.) No. 5893. Chalk Marl,
Offham. Internal cast. Natural size. a

Fig. 34.—Inoceramus Crippsi, Mantell. Chalk Marl. Internal cast of a left valve similar to the type.
British Museum (Nat. Hist.) No. 5895. Natural size.

nearly straight. Ventral margin convex ; posterior margin only shghtly convex,
and forming more than a right angle with the hinge-line. Hinge-line forms an
angle of about 140° with the antero-dorsal margin. Umbones inconspicuous,
pointed, not curved, at about a third of the length of the hinge from the anterior
end; in front of the umbones is a small, obtusely triangular ear.

Ornamentation consists of broad, rounded, rather irregular concentric ribs,
which are strong anteriorly, and become weaker posteriorly. The curvature of
the ribs is unsymmetrical; the anterior part curves rapidly, the postero-dorsal
part is only slightly curved.

Affinities —A species from the Senonian was figured and described by Goldfuss

INOCERAMUS. 277

as I. Orippsi, Mantell, and that identification has been accepted by many later
writers. The type of I. Crippsi came from the Chalk Marl (zone of Schlanbachia
varians). From a study of a cast of the type, Petrascheck and J. Bohm* came
to the conclusion that the Senonian species is quite distinct from I. Crippsi, and
Béhm has named the former J. balticus. Bohm also supports the view first
suggested by Messrs. E. T. Newton and A. J. Jukes-Browne, and confirmed by

fore a no oe

Fic. 35.—Inoceramus Crippsi, Mantell. Upper Greensand, Haldon. Right valve. British Museum (Nat.
Hist.), No. L17201. Natural size.

Petrascheck, that J. latus of Goldfuss and of d@’Orbigny (but not of Mantell) is
identical with J. Crippsi, Mantell. After a careful study of the type and other
similar specimens of I. Crippsi, and of specimens of J. latus, I can fully support
these conclusions.

I. cuneiformis, d’Orbigny,’ is allied to I. Crippsi, but is relatively higher. One
specimen found in the Upper Greensand of Warminster (Plate XLVIL, fig. 3),

1 «Subhercyn. Kreidemulde ’ (1909), pp. 41—46; Petrascheck, “Inoceram. a, d. Gosau,” ‘ Jahrb.

d. k. k. geol. Reichsanst.,’ vol. lvi (1906), p. 155.
2 « Pal. France. Terr. Crét.,’ vol. iii (1846), p. 512, pl. eccevii.

oo
|

278 CRETACEOUS LAMELLIBRANCHIA.

shows some resemblance to I. ewneiformis, but is probably only a rather high form
of I. Crippsi, with which species it is found associated.
I. orbiculavis, Goldfuss,' is regarded by Bohm as a small form of L. Crippsi,

Mantell.
Type.

In the British Museum (fig. 33) from the Chalk Marl (zone of Schlan-
bachia varians) of Offham.

Distribution.—Upper Greensand of Haldon. Upper Greensand (zone of Pecten
asper) of Warminster and Devizes. Chalk Marl (zone of Schlanbachia varians) of
Ringmer, Hamsey, Offham, Maiden Newton, Egegardon Hill, Pyrton, Chalton,
Arlesey, Hunstanton, and Donnington (Lincolnshire). Cenomanian of Wilmington
(Devon). Lower Chalk (zone of Holaster subglobosus) of Totternhoe, Burham, and
Cherry Hinton.

InoceraMus Crirest var. REACHENSIS, Htheridge, 1881. Plate XLVILI, figs. 4, 5;
Plate XLIX, fig. 1.

1881. InocrRAMUS LATUS Var. REACHENSIS, R. Etheridge. In Penning and Jukes-
Browne, Geol. Cam-
bridge, p. 142, pl. i,
fig. 3.

Remarks.—In this form, which is mainly characteristic of the zone of Holaster
subylobosus, the ribs are more sharply defined, their ventral curvature is greater,
and their posterior part is less nearly straight than in I. Cripps.

Type.—From the Totternhoe Stone of Burwell, in the Sedgwick Museum,
Cambridge.

Distribution.— Chalk Marl of Blue Bell Hill, Burham. Zone of Holastev sub-
globosus of Merstham and Blue Bell Hill, Burham. ‘Totternhoe Stone (zone of
H. subglobosus) of Burwell. Recorded by Etheridge from the Chalk Marl of
Reach.

gs. 2—4.

Inoceramus Erurripert, nom. nov. Plate XLIX, fi

1881. Inoceramus convexus, It. Etheridge. In Penning and Jukes-Browne,
Geol. Cambridge, p. 143, pl. ii,
fig. 6.
— — — var. QUADRATUS, Itheridge. Ibid., p. 143, pl. u,
fig. 7.
- STRIATUS var. convEXuUS, A. J. Jukes-Browne. Cret. Rocks of
Britain, vol. ui, p. 476.

1 «Pet ref. Germ.,’ vol. ii (1836), p- ll ts pl. exiii, fig. 2, Bohm, ‘ Subhercyn. Kreidemulde’ (1909),

p- 46, pl. xi, fig. 1.

INOCERAMUS. 279

Non 1855. Inocrramus convexus, J. Halland F. B. Meek. Foss. Cret. Nebraska (Mem.
Amer. Acad. Arts and Sci,
vol. v), p. 386, pl. ii, fig 2.

Description.—V alves nearly equal, considerably inequilateral, tumid, compressed
near the postero-dorsal margin ; height greater than length. Antero-dorsal margin
nearly straight; ventral margin usually very convex ; posterior margin slightly
or moderately convex, forming an obtuse angle with the hinge-line. Anterior
marginal parts more or less nearly perpendicular to the plane of the valves, some-
times concave near the umbo. Umbones terminal, curved inwards and forwards.
Angle between the hinge-line and the anterior margin is about 115°. The height
of the shell is nearly twice the length of the hinge. .

Ornamentation consists of faintly marked concentric undulations and numerous
erowth-lines.

Afjinities—In this species the antero-dorsal margin is relatively longer and
more nearly straight, and the postero-dorsal part of the shell less compressed than
in I. tenuis, Mantell.

1. converus var. quadratus, Etheridge, was founded on a specimen in which the
anterior part of the shell is pressed in, giving rise to the appearance of a carina
at the upper margin of the antero-dorsal slope.

Types —F¥rom the Totternhoe Stone of Burwell, in the Sedgwick Museum,
Cambridge.

Distribution—Upper Greensand (zone of Pecten asper) of Warminster.
Cenomanian of Wilmington, Devon. Chalk Marl of Branscombe, Beer Head,
Titherleigh (near Chard) and Hunstanton. Totternhoe Stone (zone of Holaster

subglobosus) of Burwell.

Troceramus picrus, Sowerby, 1829. Plate XLIX, figs. 5,6. Text-fig. 36.

1829. Inocreramvus picivs, J. de C. Sowerby. Min. Conch., vol. vi, p. 215, pl. deiv,

fig. 1.
1854. — pictus, J. Morris. Cat. Brit. Foss., ed. 2, p. 170.
1867. — ancuLatus, EL. Guéranger. Album Paléont. de la Sarthe, p.

20, pl. xxv, fig. 7 (? I. aNGuLAtTUs,

d’ Orbigny, 1846).
1904. ~ pictus, EF. T. Newtonand A.J.Jukes-Browne. In Jukes-Browne,
Cret. Rocks of Britain, vol.

iii, p. 450.

Description.—Shell equivalve, very inequilateral, slightly or moderately convex

with flattened sides; the postero-dorsal part compressed. Antero-dorsal marginal

280 CRETACEOUS LAMELLIBRANCHIA.

part flattened or concave, and more or less nearly perpendicular to the plane of
the valves. Ventral margin very convex; posterior margin moderately convex.
Umbones terminal, incurved. Hinge-line nearly at right angles to the anterior
margin. Ornamentation consists of numerous strong, somewhat irregular concen-
tric ribs, separated by concave interspaces. The curvature of the ribs is
unsymmetrical, and the ribs become less distinct on the antero-dorsal and postero-
dorsal parts of the valves.

Affinities.—This species shows some resemblance to I. anglicus, but possesses
more numerous ribs, and also differs in the anterior part of the shell being flat or

Fie, 36.—Inoceramus pictus, Sow. Chalk Marl, Guildford. British Museum No. 43272. The Type.
Natural size,
concave. The type and some other specimens (ec. g. No. 73339, British Museum)
show traces of the original colouring of the shell. An example of this species
was figured by Guéranger as J. angulatus, @Orbigny,' but appears to be quite
distinet from that form.
From the Chalk Marl of Guildford, in the British Museum (Natural

Type.
History).

Distribution.—Lower Chalk (zone of Holaster subglobosus) of Beachy Head,
Burham, Rochester, and the Gog-ma-gogs, near Cambridge. Chalk Marl of
Burham and Guildford.

1 «Pal. Franc. Terr, Crét.,’ vol. iii (1846), p. 515, pl. ecceviii, figs. 3, 4. In the text the spelling

is angulosus.

Ivoceramus Lapiarus (Schlotheim), 1813.

1768.

? 1852.

1854.
1863.

?1870.

1871.

INOCERAMUS. 281

Plate L. Text-fig. 37.

Osrracires, J. H. I. Walch. Die Naturgesch. Verstein z. Hrliiut. d.
Knorrischen Sammil. v. Merkwiirdigk. d.
Nuatur., II, p. 84, pl. B ILd*, fig. 2;
p. 152, pl. dx, figs. 1, 2.

-—— LABiatus, H. FF. v. Schlotheim. In Leonhard’s Taschenbuch
fiir Min., vol. vii, p. 93.

Pinnites pituvianus, Schlotheim. Ibid., p. 93.

-—- _- Schlotheim. Petrefactenk., p. 303.
Myriuorpes Lasrarus, A. Brongniart. Iu Cuvier, Ossemens Fossil s, vol. ii,
pt. 2, pp. 320, 597, pl. in, fig. 4.
InocErAMuS MytTrILLorpEs, G. Mantell. Foss. 8. Downs, p. 215, pl. xxvii,
fiz. 3; pl. xxviii, fig. 2.

— mytiLorEs, J. de C. Sowerby. Min. Conch., vol. y, p. 62,
pl. cecexlii (not the two
smaller figures).

Carintum Scuiotuermt, S. Nilsson. Petrif. Suecana, p. 19.

Petref. Germ., vol. ii, p. 118, pl.
exill, fig. 4.

InocerAmus mytrLoipEs, A. Goldfuss.

Polens Paliiont., p. 45.
Die Verstein. d.
Kreidegeb., p. 63.

Carrtuus mMytinorpEs, G. G. Pusch.

Inoceramus mytiLorpeEs, Ff. A. Rimer. nord-deutsch.

— PROBLEMATICUS, A. d’Orbigny. Pal. Franc. Terr. Crét., vol.

iii, p. 510, pl, cecevi, figs.
1—7 (Non. I. problematicus,
vy. Schlotheim).

Die Verstein. der bohm. Kreide-
format., pt. 2, p. 26, pl. xxxvui,
fig. 16.

Grundr. d, Verstein., p. 463.

Mém. Soe. géol. de France, ser. 2,

— MyTILOIDES, A. HL. Reuss.

— — H. B. Geinitz.
— —- A. d’ Archiae.
vol. ii, p. 307.

proBLEMAticus, A. d’Orbigny. Prodr. de Pal., vol. 11, p. 197.

Das Quadersandst. oder Kreide-
geb. in Deutschland, p. 176.

— — F. Rimer. Kvreidebild. v. Texas, p. 60, pl. vii,

fig. 5.

a J. Morris. Cat. Brit. Foss., ed. 2, p. 170 (partim).

myriLorpEs, H. B. Geinitz.

—_— —_ A. v. Strombeck. Zeitschr. d. deutsch. geol.

Gesellsch., vol. xv, p. 119.

_— Larus, F. Rémer. Geol. v. Oberschles., p. 316, pl. xxxiy,
fig. 12.

_- Lapiatus, F. Stoliczka. Palwont. Indica, Cret. Fauna 8.

India, vol. iii, p. 408, pl. xxix,

fig. 1.

282 CRETACEOUS LAMELLIBRANCHIA.

1872. Inoceramus Laprarus, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal-
wontographica, vol. xx, pt. 2),
p. 46, pl. xii, figs. 1—3.

1873. -—- — Geinitz. Neues Jahrb. fiir Min, ete., p. 13.
1877. = : C. Schliiter. Palseontographica, vol. xxiv, p. 262.

= A. Fritsch. Stud. im Gebiete der béhm. Kreide-
format. 11, Weissenberg. u. Malnitz.
Schicht., p. 130, fig. 112.
? 1888. - - S. Nikitin. Les Vestiges Crét. Russ. centrale
(Mém. Comité eéol. Russ., vol. v,
no. 2), p. 34, pl. 5, figs. 10, 11.

1888. A. Peron. Hist. Terr. de Craie dans le S.E. du
Bassin Anglo-Parisien, p. 158.
1893. - = R. Michael. Zeitschr. der deutsch. geol. Gesellsch.,

vol. xlv, p. 241.
- - —- T. W. Stanton. The Colorado Formation (Bull.
U.S. Geol. Surv., No. 106), p.

77, pl. x, fig. 4; pl. xiv, fig. 2.

? 1897. ~ — R. Leonhard. Wreideformat. in Oberschles. (Pal-
wontographica, vol. xliv), p. 48.
1903. — — W. Petrascheck. Jahrb. d. k. k. geol. Reichsanst.,
vol. lili, p. 156.
? Non 1868. -- myTILoIDEs, H. Hichwald. Lethea Rossica, vol ii, p. 492, pl.
xxi, fig. 6.
-— 1881. a (Myritires) propiematicus, R. Etheridge. In Penning and

Jukes-Browne, Geol. Cambridge,
p. 148, pl. iii, figs. 9—11.

Description.—Shell mytiliform, nearly equivalve, extremely imequilateral,
oblique, much elongated between the umbo and the postero-ventral extremity,
convex, with a small posterior ear; antero-dorsal part sloping steeply and some-
times concave. Angle formed by the hinge with the antero-dorsal margin about
90°, Umbones terminal, with a slight anterior curvature. Anterior margin gently
curved; postero-ventral extremity very convex; posterior margin nearly straight.

Ornamentation consists of small, fairly regular concentric undulations, which
have an unsymmetrical curvature in the young, but become more nearly symmetrical
in older specimens. On the old parts of the shell the undulations become less
distinct.

Affinities—It seems probable that this species is related to I. Cripps var.
reachensis (p. 278), but the height of the shell is relatively greater, the length of
the hinge-line is less, and the direction of growth is oblique to the hinge-line.

I. propinquus, Goldfuss,' from the Quader-sandstone of Schandau, was regarded
by Geinitz as a synonym of J. labiatus.

1 « Petref. Germ.,’ vol. ii (1836) p. 112, pl. eix, fig. 9.

INOCERAMUS. 283

D’Orbigny identified this species with L. problematicus, von Schlotheim, which
comes from the Senonian, and has been shown by Béhm to be distinct from the
Turonian form!

Remarks.—This species is mainly characteristic of the zone of Rhynchonella
Cuvieri. In the zone of Terebratulina lata it is not common, and the shell is
usually relatively longer than in typical forms of the species.

Types.—The type came from the Turonian of Pirna. The specimens figured by
Mantell from the zone of Rhynchonella Cuvieri of Plumpton are in the British
Museum. The large specimen figured by Sowerby from Warminster cannot be
found.

Distribution.—Zone of Rhynchonella Cuvieri of the Devon and Dorset coasts, the
Isle of Wight, Winchester, Hastbourne, Lewes, Plumpton, Dover, Blue Bell Hill
(Burham), Betchworth, Watlington (Berkshire), Hitchin, Cherry Hinton, South
Thoresby, South Ferriby (Lincolnshire), and the Yorkshire coast. Zone of
Terebratulina lata of the Devon and Dorset coasts, Winchester, Eastbourne, and
Dover.

Recorded by Jukes-Browne from the zone of Holaster subglobosus of Cambridge-

Fic. 37.

Fia. 38.

Fic. 37.—Inoceramus labiatus (Schloth). The type of Inoceramus mytiloides, Mantell, ‘ Foss. S. Downs,’
p. 215, pl. xxviii, fig. 2. Zone of Rhynchonella Cuvieri, Plumpton. British Museum. Natural size.
Fic, 38.—Inoceramus lubiatus var. latus, Sow. Zone of Holaster planus, Purley Junction Station. British
Museum, No. L21194. Natural size.

1 J. Bohm, ‘ Monatsber. d. deutsch. geol. Gesellsch.’ (1909), p. 117.

284. CRETACEOUS LAMELLIBRANCHIA.

shire and West Norfolk ; and by Rowe from the zone of Holaster planus of Dover
and the Sussex coast, and from the zone of Micraster cor-testudinarium of Dover.

Fig. 39. Fia. 40.

Fic. 39.—Inoceramus labiatus var latus, Sow. Zone of Holaster planus, Swaffham, Norfolk. Norwich
Museum, No. 3296. Right valve and anterior view. Natural size.
Fic. 40.—Imoceramus labiatus var. latus, Sow. One of the types of Inoceramus latus, Sowerby, ‘ Min. Conch.,’
vol. vi, p. 159, pl. dlxxxii, fig. 1 (lower figure). Swaffham. British Museum, No, 43266. Natural size.

INOCERAMUS LABIATUS var. LATUS, Sowerby, 1828. Text-fios. 38—4.0.
> J) to}

1828. Inocrramus tatus, J. de C. Sowerby. Min. Conch., vol. vi, p. 159, pl.
dixxxii, fig. 1. (Non JI. latus,
Mantell).

1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 170 (partim).

Remarks.—Vhis variety differs from I. labiatus in the much greater length of
the hinge-line in proportion to the height of the shell, in the greater convexity of
the anterior margin, the smaller convexity of the ventral margin, and the less
oblique form of the shell. On account of the greater length of the hinge-line the
curvature of the ribs and growth-lines is broader than in I. labiatus.

This variety appears to be confined to the zone of Holaster planus, and is
common in the neighbourhood of Swaffham, Norfolk. The larger specimens which
I have seen are not sufficiently perfect for figuring, but a characteristic example
is figured by Sowerby.

Types.—From the zone of Holaster planus of Swaffham. The smaller specimen
figured by Sowerby is in the British Museum (Fig. 40), but the larger specimen
sannot be found.

Distribution.—Zone of Holaster planus of Purley Junction Station, Surrey, and
Swaffham, Norfolk.

Palxontographical Society, 1911.

x SEO: N- OG Ae

CRETACKOUS LAMELLIBRANCHIA

ENGLAND.

BY

HENRY WOODS, M.A.
ERSITY LECTURER IN PALZOZOOLOGY, CAMBRIDGE

WONT, 100 TAR Wa
INOCERAMUS (continued).

Paces 285—340; Pirates LI—LIV.

LONDON:
PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY.
1912.

PRINTED BY ADLARD AND SON, LONDON AND DORKING.

INOCERAMUS. 285

Fic. 41.—Inoceramus labiatus var. latus, Sow. Zone of Holaster planus, Coombe Bissett. Dr, Blackmore’s
Collection. Right valve. Natural size.

INocERAMUS INCONSTANS, sp. nov. Plate LI, figs. 1—4. Text-figs. 39, 42—49.

t=)

1822. Inocrramus Bronenrartt, var., G. Mantell. Foss. 8. Downs, p. 215, pl.
Xxvili, fig. 3.

-- _- sp. Mantell. Ibid., p. 217, pl. xxvii, fig. 9.

1850. — Lamarcen, J. de C. Sowerby in F. Dizon. Geol. Sussex, p.
395 (p. 385, ed. 2),
pl. xxviii, fig. 29.

1904. - Bronenrartit, C. Airaghi. Boll. Soc. geol. Italiana, vol. xxiii,

p. 192, pl. iv, figs. 3—5.

Description.—Shell extremely inequilateral, moderately or slightly inequivalve ;
the early part of the shell slightly convex or nearly flat, the later part much more
convex and sometimes growing nearly perpendicularly to or forming a large angle
with the early part, so that in old individuals the shell becomes more inflated ; in
other cases the convexity increases more gradually from the earlier to the later
stages of growth and a nearly globose shell results. Height of the shell often
rather greater than the length. Hinge-line long, forming rather more than a
right angle with the anterior margin, which is usually more or less nearly straight.
Ventral and posterior margins rounded. Umbones terminal, small, pointed, only
slightly curved. Anterior marginal part of the valve usually flattened, but not
definitely limited from the sides of the shell. Posterior ear developed but not
distinctly limited.

Concentric folds are usually well developed, but become indistinct on the
anterior flattened area, on the posterior ear, and on the later part of the valve
of old individuals. The concentric folds have a very unsymmetrical curvature.

Remarks.—The forms included in this species vary considerably, owing mainly
to the length of duration of the flattened stage, which in some individuals forms a

38

286 CRETACEOUS LAMELLIBRANCHIA.

small part (Figs. 43, 48, 49) but in others a large part (Plate LI, fig. 2, Text-figs.
45, 46) of the entire shell.’ Also the passage from one stage to the other is
sometimes gradual, so that the section of the shell forms a fairly uniform curve

(Fig. 48), but generally the change is abrupt, so that the later part of the valve is

Fic. 42.—Imoceramus inconstans, sp. nov. The original of Inoceramus sp., Mantell, ‘ Foss. S. Downs,’ p. 217,
One ! a8 Bus AE se Se
pl. xxvii, fig. 9. Upper Chalk, Lewes. British Museum, No. 4765. Left valve and posterior view.
Natural size.

Fig. 43.—Inoceramus inconstans, sp. nov. Zone of Holaster planus, Swattham, Norfolk. Norwich Museum.
Left valve, and posterior and dorsal views of the same, Natural size.

bent at an anele with the earlier part (Figs. 42, 43). The length of the hinge-line
in proportion to the height of the shell shows some variation and consequently the

1 The larger specimen of I. latus, Sowerby (‘ Min. Conch.,’ vol. vi, pl. dlxxxii, upper figure),
5 , i) be

which cannot now be found, is probably an example of this.

Fic. 44.

Fic. 44.—Inoceramus inconstans, Sp. noy.
p. 215, pl. xxviii, fie. 3.
Museum, No. 5878. Right valve.

The original of I. Brongniarti, var., Mautell, ‘ Foss. S. Downs,’
Upper Chalk (probably zone of Micraster cor-anguinum), Southeram. British

Natural size.
Fria, 45.—Inoceramus inconstans, sp.nov. Upper Chalk, Sussex. British Museum, No. 5865. Left valve
and anterior view. Natural size.

EROTTSET FE

y Vif VAG, >
f F J iar nn oa
y i edi fe

—
, aa s
PEE. Fae

Fic, 46.—Inoceramus inconstans, sp. nov. Zone of Holaster planus, Swaffham, Norfolk. Norwich Museum,
Right valve. Natural size

288 CRETACEOUS LAMELLIBRANCHIA.,

curvature of the ribs varies. In some specimens (often of large size) the shell
is thinner than usual and has sharp and ridge-like folds similar to those of
I. Lamareki var. Websteri, Mant. (p. 318). Further work may show that it is
desirable to give names to some of the varieties of I. inconstans.

Affinities. —This species is closely allied to J. labiatus var. latus, Sowerby ;*
but the hinge is relatively longer and the height of the shell less, the anterior
flattened area is larger, the later part of the shell is more convex, the umbones

are less prominent and the posterior ear more distinct.

Fie. 47.—Inoceramus inconstans, sp. nov. Upper Chalk (zone of Actinocamaz quadratus), Brighton.
Brighton Museum, No, 336. Right valve and anterior view. Natural size.

I. inconstans is distinguished from I. Lamarcki, Parkinson (p. 307), by the
relatively longer hinge-line, the more unsymmetrical curvature of the folds, the
flattened form of the early part of the shell, the less prominent umbones, and
the smaller difference in the size of the valves. 1. Cuvieri of Andert® appears to
be a flat form of J. inconstaus. Another specimen figured by Andert® is allied to
I. inconstans, but its axis of growth is more oblique and its hinge longer than usual.

1 Erratum on p. 284 (fig. 89) : for Inoceramus labiatus var. latus, Sow., read Inoceramus incon-
stans, sp. nov. A specimen figured by Andert (‘Inoceramen d. Kreibitz-Zittauer Sandsteingeb.,’ 1911,
p. 45, pl. i, fig. 5) as I. Cuvieri var. planus appears to be intermediate between J. /abiatus and I. labiatus
var. latus.

2 Loe. cit., pl. ii, fig. 2

8 Loe. cit., pl. i, fig. 2, pl. vii, fig. 8 (I. Cuvieri var. planus).

INOCERAMUS. 289

iu ¥

i

Fig. 48.—Inoceramus inconstans, sp. nov. Upper Chalk. Locality unknown, British Museum, No. 30832.
Left valve and dorsal view. «x §.

290 CRETACEOUS LAMELLIBRANCHIA.

Fic. 49.—Inoceramus inconstans, sp. nov. Zone of Actinocamaw quadratus, East Harnham, Salisbury. Dr.
Blackmore’s Collection. Left valve and dorsal view. Natural size.

INOCERAMUS. 291

T'ypes.—The specimen figured by Mantellas /. Brongniarti var., from the Upper
Chalk (probably zone of Micraster cor-anguinum) of Southeram (Lewes), and the
one figured as Inoceramus sp. by the same author from Lewes, and [. Lamuarcki,
Sowerby (in Dixon), from the Chalk, Sussex (probably zone of Terebratulina
lata of Malling), are in the British Museum, Nos. 5878, 4765, 120955 respectively.

Fic. 50—Inoceramus inconstans, sp.nov. var. Senonian, Haldon. British Museum, No. L17380. Left valve.
A large flat form resembling I. cycloides, Wegner. Compare with Fig. 46. x {.

Distribution.—Zone of Holaster planus of Twyford, Swaffham (Norfolk), and
Strood. Zone of Micraster cor-testudinarium of Chatham, Guilford Colliery
(Coldred near Dover), and Wharram (Yorkshire). Zone of Micraster cor-anguinum
of Southeram (Lewes). Zone of Actinocamax quadratus of Kast Harnham
(Salisbury) and Brighton. Zone of Belemnitella mucronata of Shide (Isle of
Wight). Probably also in the zone of Verebratulina lata.

CRETACEOUS LAMELLIBRANCHIA.

INOCERAMUS INCONSTANS var. stRIATUS, Mantell, 1822. Plate LI, fig. 5; Plate LII,

Non

fig. 1.

1822. Inocrramus striatus, G. Mantell. Foss. 8. Downs, p. 217, pl. xxvii, fig. 5.

J. de C. Sowerby. Min. Conch., vol. vi, p. 160, pl.
dlxxxii, fig. 2.
J. Morris. Cat. Brit. Foss., ed. 2, p. 170 ( partim).

A. Goldfuss. Petref. Germ, vol. ii, p. 115, pl. exii,
fig. 2.
F. A. Rimer. Die Verstein. d. nord-deutsch.
Kreidegeb , p. 62.
A. H. Reuss. Die Verstein, der bohm. Kreidefor-
mat., pt. 2, p. 25.
A. dOrbigny. Pal. Franc. Terr. Crét., vol. iii, p.
508, pl. eecev.
d’Orbigny. Prodr. de Pal., vol. ii, p. 168.
F. Rimer. Wreidebild. v. Texas, p. 60.
A. v. Strombeck. Zeitschr. d. deutsch. geol. Gesell-
sch., vol. xv, p. 108.
A, Kunth. Ibid., vol. xv, p. 727. ‘
F. Rimer. Geol. v. Oberschlesien, p. 340, pl. xxix,
fig. 6.
H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal-
eontographica, vol. xx, pt. 1),
p- 210, pl. xlvi, figs. 9—13; (ibid.,
pt. 2), p. 41, pl. xiii, figs. 1, 2,
0}
Geinitz. Neues Jahrb. fiir Min., ete., p. 7.
A. Fritsch. Stud. im Gebiete der bohm. Kreide-
format. ii, Weissenberg. u. Malnitz.
Schicht., p. 129.
J. Kiesow. Schrift. nat. Gesellsch. Dantzig, vol. v,
p- 413.
F. Notling. Die Fauna d. baltisch. Cenoman. (Pal-
wont. Abhandl., vol. ii), p. 23, pl. ii,
figs. 11, 12.
R. Michael. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xlv, p. 233.
E. Tiessen. Ibid., vol. xlvii, p. 480.
H. Woods. Quart. Journ. Geol. Soc., vol. liii, p. 381,
pl. xxvii, fig. 13.
A. Fritsch. Stud. im Gebiete béhm. Kreideformat.
(Erginzung zu Bd. I, Korycaner
Schicht.), p. 42, fig. 190.

INOCERAMUS. 293

Remarks.—This variety, which is uncommon and of small size, is distinguished
by the strongly inflated valves, the large angle between the hinge-line and the
anterior border, the absence of folds, and the absence or indistinct character of
the anterior flattened area and of the posterior ear.

Types.—The type, from the zone of Micraster cor-anguinum of Southeram,
Lewes, is in the British Museum, No. 4768 (Plate LI, fig. 5). The specimen
figured by Sowerby from the Upper Chalk (probably zone of Holaster planus) of
Heytesbury is also in the British Museum, No. 43267.

Distribution.—Zone of Holaster planus of Stonehall siding near Dover, and
Swaffham, Norfolk. Zone of Micraster cor-anguinum of Southeram. Upper
Chalk (probably zone of Holaster planus), Heytesbury.

INOCERAMUS INCONSTANS var. SARUMENSIS, var. nov. Plate LIT, figs. 2, 3.

A variety found in the zone of Actinocamax quadratus of East Harnham
(Salisbury), Mottisfont, and West Meon (Hampshire), is distinguished by the
umbones being more prominent and not terminal, by the regular convexity and
equal size of the valves, the absence of the anterior flattened area, and the absence
or indistinct character of the concentric folds. This variety is connected with
typical forms of the species by some examples (Fig. 49) in which the early part of
the shell is less convex and possesses distinct folds, but the umbones are not quite
terminal and the anterior flattened area is not present. J. tnconstans var.
sarumensis appears to resemble I. Brancoi, Wegner,’ of which good figures have

not yet been published.

INoceramous BALticus, Bohn, 1907. Text-fies. 51—53.

5

1836. Inoceramus Cripsu, A. Goldfuss. Petref. Germ., vol. ii, p. 116, pl. exii,
fig. 4b. (Non I. Crippsi, Mantell, 1822).

1870. — — var. sutcatra, F. Riimer. Geol. v. Obersebles., p. 356,
pl. xxxix, fig. 9.
1907. — BALTICUS, J. Bohm. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. lix, Monatsber., p. 113.
1909. — Bohm. Subhereyn. Kreidemulde (Abhandl. d. k.

preuss. geol. Landesanst ; N.F. 56), p. 47,
pl. xi, fig. 2a, pl. xii, fig. la.
1910. — — J. Nowak. Bull. Internat. Acad. Sci. Cracovie
(1909), p. 875.

1 ‘ Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. lvii (1905), p. 159, fig. 4.

294. CRETACEOUS LAMELLIBRANCHIA.

Deseviption.—Shell equivalve, very inequilateral, slightly or moderately convex,
becoming very convex in old specimens, in which the later part of the shell grows

either perpendicularly to or at an obtuse angle with the earlier part; posterior

Fie. 51.—Inoceramus balticus, Bohm. Senonian, Worbarrow Bay, Dorset. British Museum, No. L22177.
Flint cast. Right valve and anterior view. Natural size.

Fia. 52.—Inoceramus balticus, Bohm. Anterior view of specimen shown in Fig. 53. x 4.

and postero-dorsal parts compressed; length greater than height, the difference
increasing with age. Anterior and ventral margins rounded; posterior margin
forming an obtuse angle with the hinge. Huinge-line long. Umbones rather

small, nearly terminal.

INOCERAMUS. 295

Concentric ribs strong, sharp, narrow, with a very unsymmetrical curvature ;
a few ribs may come off from the sides of other ribs; between the ribs are broad
concave interspaces. On the marginal parts of old specimens ribs are absent.

Affinities—I. halticus is closely allied to I. inconstans, from which it has

Fic. 53.—Inoceramus balticus, Bohm. Upper Chalk (probably zone of Marsupites testudinarius), Brighton,
Museum of Practical Geology, No. 25509. Left valve and dorsal view. x 3

probably been derived; it differs from that species by its longer hinge and the
longer shell, with the umbones not quite terminal. The length of duration of the
slightly convex stage varies in the same way as in J. inconstans. The specimen of
I. inconstans shown in Fig. 45 makes, on account of its longer hinge, some
approach to I. balticus.'

1 See also Bol, loc. cit., pl. xii, fig. la.

296 CRETACEOUS LAMELLIBRANCHIA.

I. veqularis, VOrbigny,! differs from J. balticus in the outline of the shell, in its
uniform convexity, and in the broader and less sharp ribs.

Some of the forms from Gosau referred by Zittel to [. Crippsi resemble closely
IT. balticus.?

Type.—From the Lower Quadratus beds of Diilmen, in the Paleontological
Institute of the University of Bonn.

Distribution.—Senonian of Haldon, and Worbarrow Bay (Dorset), and Brighton
(probably zone of Marsupites testulinarius). Gone of Actinocamax quadratus of
Mottisfont, Ropley (Hants), East Harnham (Salisbury), Mount Pleasant near
Andover, Driffield, and Sewerby (Yorkshire). Zone of Belemiuitella mucronata of
Clarendon and Fareham (Hants), Alum Bay and Shide (Isle of Wight), and Norwich.

Inoceramus Lopatus, Goldfuss, 1836. Text-figs. 54, 55.

1836. Inoceramus Losatus, A. Goldjuss. Petref. Germ., vol. ii, p. 113, pl. ex,

fig. 3.
1877. — — C. Schliiter. Paleontographica, vol. xxiv, p. 275,
pl. xxxix, figs. 1, 2.
1882. — — H. Schrider. Zeitschr. d. deutsch. geol. Gesellscb.,
vol. xxxiv, p. 272.
¢ 1888. — off. toparus, S. Nikitin. Les Vestiges Crét. dans la Russie

Centrale (Mém. Comite Géol.,
vol. v, no. 2), p. 34, pl. v, fig. 12.
= = LoBAtus, G. Miller. Jahrb. d. k. preuss. geol. Landesanst.

fur. 1887, p. 415.

1889. = — E. Holzapfel. Die Mollusk. Aachen. Kreide (Pale-
ontographica, vol. xxxv), p. 223.
? 1894. — aff. Loparus, K. Jimbo. Wreideformat. v. Hokkaidd (Pal-

wont. Abhandl., vol. vi), p. 44,
pl. viii, fig. 11.
1898. -- Lopatus, G. Miller. Mollusk. Untersen. v. Braunschweig. u.
Tlsede (Abhandl. d.k. preuss. geol.
Landesanst., N.F., 25), p. 43, fig. 10.

? 1901. — ef. Lopatus, Ff. Sturm. Jahrb. d. k. preuss. geol. Landesanst.
fiir 1900, vol. xxi, p. 93, pl. x, fig. 3.
1902. — Lopatus, A. Wollemann, Limeburg. Kreide (Abhandl. d. k.

preuss. geol. Landesanst., N.F., 37),
joy (ile
1 «Pal. Frang. Terr. Cret.,’ vol. iii (1846), p. 516, pl. eecex.
* Compare also I. Cripsi var. suleata, Romer, ‘ Kreidebild. vy. Texas’ (1852), p. 56, pl. vii, fig. 2,
and J. Cripsianus, Stoliczka, ‘Paleont. Indica, Cret. Fauna S. India,’ vol. iii (1871), p. 405,
pl. xxvii, figs. 1—3; pl. xxviii, fig. 2, and I. crassus, Petrascheck, ‘Jahrb. d. k. k. geol. Reichsanst.,’ vol.
lin (1903), p. 164, pl. viii, fig. 4, and Andert, ‘ Inoceramen d. Kreibitz-Zittauer Sandsteingeb.’ (1911),
p- 46, pl. iii, fig. 4, pl. vi, figs. 1, 2.

INOCERAMUS. 297

1902. Inoceramus tosatus J. P. J. Ruvn. Mollusk. i Danmarks Kridtafl. I.
Lamellibr., p. 103.

1905. — - T. Wegner. Zeitschr. d. deutsch. geol. Gesellsch.,

vol. lvii, p. 164, fig. 7, pl. x, figs. es

e

and text-fig. 7.

1906. = — G. Smolenski. Bull. Internat. Acad. Sci. Cracovie,
p- 722, pl. xxvii, figs. 16-18.
1909. — -— J. Nowak. Ibid (1909), p. 875.

Fic. 54.—Inoceramus lobatus, Goldf. Zone of Actinocamaxz quadratus, East Leys, Yorkshire. British Museum,
No. L23910. Internal cast of right valve; posterior wing missing. x §.

Description.—Shell very inequilateral, oblique, compressed, slightly convex—
the anterior part more convex than the posterior part; much higher than long.
Antero-dorsal marginal part sloping steeply. Ventral margin convex, with a

298 CRETACEOUS LAMELLIBRANCHIA.

shallow sinus near the postero-ventral angle. Posterior margin nearly straight,
somewhat oblique, forming an angle with the ventral margin. A broad shallow
depression extends from behind the umbo to the postero-ventral sinuosity ;
posteriorly this depression is limited by an angular ridge. Behind the ridge is a

Fig. 55.—Inoceramus lobatus, Goldf. Zone of Actinocamax quadratus, Yorkshire. York Museum. Part of

left valve. x %.

flattened or slightly concave wing-like part which, owing to the thinness of the
shell, is often not preserved. Umbones acute, near the anterior end.

Ornamentation consists of concentric ribs with an unsymmetrical curvature ; in
the posterior depression the ribs bend upwards, forming a sinuosity, and on the
wing the ribs bend upwards and are less distinct than elsewhere. The concentric
ribs are of two sizes; large ribs occur at intervals and between these are several
smaller ribs.

INOCERAMUS. 299

Affinities—Inoceramus nasutus, Wegner,' from the Senonian of Bossendorf and
Diilmen, is allied to I. lobatus. See also I. lingua, I. cardissoides, and I. tuberculatus
(below).

Remari:s—Only imperfect casts of this species have been seen, but it is
abundant in Yorkshire. In North Germany this species occurs also in the zone of
Marsupites testudinarius.

Type.—From the Lower Senonian of Quedlinburg.

Distribution—Zone of Actinocamae quadratus of Sewerby, Bessingby and
other localities in Yorkshire.

Inoceramus tineva, Goldfuss, 1856. Text-fig. 56.

1836. Inoceramus Lineua, A. Goldfuss. Petref. Germ., vol. ii, p- ese pl. cx,
fig. 5.
1877. — — OC. Schliiter. Paleontographica, vol. xxiv, p. 276,
pl. xxxix, figs. 3, 4.
1898. — — G. Miller. Mollusk. Untersen. v. Braunschweig. u.
Ilsede (Abhandl. d. k. preuss. geol.
Landesanst., N.F., 25), p. 45, pl. v,

fig. 8.

1899. — — V. Popovici-Hatzeg. Mém. Soc. géol de France, Paléont.,

vol. viii, pt. 3, p 7.
1902. — — J. P.J. Ravn. Mollusk. Danmarks Kridtafl., I.
Lamellibr., p. 102.

1905. -- — TT. Wegner. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. lvii, p. 168.

1909. — — J. Nowak. Bull. Internat. Acad. Sci. Cracovie, p. 875.

Remarks.—This species is closely allied to J. lobatus, Goldfuss, but the speci-
mens at present available are not sufficiently perfect to enable me to make a close
comparison. J. lingua appears to differ from J. /obatus in the absence of the ridge
between the umbo and the postero-ventral angle, in the absence or indistinct
character of the radial depression in front of the ridge, in the greater relative
length of the shell, and in the ribs being either of uniform size or of two sizes less
distinctly marked than in J. lobatus.

Type.—From the Senonian of Diilmen.

Distribution —Upper Chalk of Birdsall, Yorkshire. Zone of Belemunitella

1 *Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. lvii (1905), p. 167, pl. x, fig. 3, text-fig. 8.

300 CRETACEOUS LAMELLIBRANCHIA.

mucronata of Norwich. Recorded by Barrois from the zone of Marsupites
testudinarius of Rottingdean.

Fie. 56.—Inoceramus lingua, Goldf. Zone of Belemnitella mucronata, Norwich. British Museum, No.
L20956. Part of right valve. Natural size.

|
Txoceramus carpissoipes, Goldfuss, 1836. Text-figs. 57, 58.

1836. Inocrramus carpissorpEs, A. Goldfuss. Petref. Germ., vol. ui, p. 112,
pl. ex, fiz. 2.

1841. = LOBATUS Var. 8. CARDISSOIDES, F. A. Rimer. Die Verstein.
d. nord-deutsch. Kreidegeb., p. 63.
1876. — carpissorpEs, D. Brauns. Zeitschr. f. d. gesammt. Natur-
wiss., vol. xlvi, p. 377.
1877. -— —— C. Schliiter. Paleeontographica, vol. xxiv, p. 274.
1888. — = G. Miller. Jahrb. d. k. preuss. geol. Lan-
desanst. fiir 1887, p. 415.
1898. — = G. Miiller. Mollusk. Untersen. v. Braun-

schweig u. Ilsede (Abhandl. d. k.
preuss. geol. Landesanst., N.F.,
25), p. 44, fig. 11.

1902. — — A, Wollemann. Wiineburg. Kreide (Ib‘d., 37),
ps Le :
1905. — — T. Wegner. Zeitschr. d. deutsch. geol.

Gesellsch., vol. lvii, p. 169.

INOCERAMUS. 301

Non 1882. Inocrramus carpissorpEs, H. Schrider. Zeitschbr. d. deutsch. geol.
Gesellsch., vol. xxxiv, p. 271,
pl. xvi, fig. 1.

Description.—Shell very inequilateral, oblique, moderately convex, with the
anterior marginal part sloping rapidly. Height considerably greater than length.

Fie. 58.

Fig. 57.—Inoceramus cardissoides, Goldf. Upper Chalk (probably zone of Actinocamax quadratus), near
Speeton. Sedgwick Museum. Left valve. Posterior wing missing. Natural size.
Fic. 58.—Inoceramus cardissoides, Goldf. Upper Chalk, probably Kent. British Museum, No. 98209.
Part of left valve. Natural size.

Ventral margin convex; anterior margin slightly curved. A broad concave
depression extends from behind the umbo to the postero-ventral extremity, and is
limited posteriorly by a straight, sharp ridge, behind which is a wing-like part of
the shell.

Ornamentation consists of strong, widely separated concentric ribs, with a steep
ventral slope and a more gentle dorsal slope; in the interspaces are small con-

centric ribs, which are crossed by small radial ribs giving a more or less distinctly
40

302 | CRETACEOUS LAMELLIBRANCHIA.

tuberculate character to the larger concentric ribs. On the posterior part of the
shell the concentric ribs bend sharply upwards.

Remarks.—Only two imperfect specimens of this species have been seen ; it is
closely allied to I. lobatus (p. 296), but differs in the presence of radial ribs, the
greater development of the larger concentric ribs, and in the greater convexity of

the valves.

T'ype.—From the Senonian of Quedlinbure.
Distribution —Upper Chalk (probably zone of Actinocamax quadratus) near

Speeton, and the south of England (probably Kent).

INOCERAMUS TUBERCULATUS, sp. nov. Plate LIV, fig. 8. Text-fig. 59.

1882. Inoceramus carpissorpEs, H. Schrider. Zeitschr. d. deutsch. geol.
Gesellsch., vol. xxxiv, p. 271,
pl. xvi, fig. 1 (Non Goldfuss).

Description.—Shell very inequilateral, oblique, much higher than long; dorsal
part moderately convex, ventral part only slightly convex. Umbones relatively
small, nearly terminal. Antero-dorsal area flattened, nearly smooth. A rounded
depression, separated from the posterior wing-like part, passes from the umbo to
the postero-ventral extremity. Hinge-line forms less than a right angle with the
anterior margin.

Ornamentation consists of numerous concentric ribs which, at a short distance
from the umbo, are crossed by radial furrows, so that the ribs appear then
to consist of rows of tubercles; on the sides of the shell the radial furrows,
and consequently also the tubercles, are less distinct than on the middle of
the shell.

Affinities —This species is allied to I. lobatus and I. cardissoides, but differs in
the greater development of the radial ribs, which give rise to a tuberculate type
of ornamentation ; also the stronger concentric ribs which occur in J. cardissoides
are small or altogether wanting. The English specimens agree fairly closely with
the example figured by Schréder as J. cardissoides.

T'ype—In Dr. Rowe’s Collection.

Distribution.—Upper Chalk (zone of Actinocamar quadratus) of Brighton, and

Sewerby (Yorkshire).

Fic. 59.—Inoceramu

paacle

‘Dr. i Wy. ee

INOCERAMUS.

a) oe 5: v¢
. pene jt

Zone of
Collection. Part ecient, ates

re,
ay

NX ae

re werby,

Y

orkshire,

303

304: CRETACEOUS LAMELLIBRANCHIA.

INOCERAMUS UNDULATO-PLICATUS, LtGmer, 1852. Text-figs. 60, 61.

t=)

1852. InocreRamMus uNpuULATO-PLIcaAtUS, F. Rimer. Kreidebild. v. Texas, p. 59,
pl. vii, fig. 1.

1865. — piairatus, Ff. A. Riimer. Paleontographica, vol. xiii, p. 196,
pl. xxxu, fig. 6.
1873. — — F. Schmidt. Mém. Acad. Imp. Sci. de St.

Pétersb., ser. 7, vol. xix, no. 3,
p- 25 (partim), pl. v, figs. 10, 11 ;
pl. vi, fic: 1, 2,4, 6, 75 pl. vu;
pl. vui, figs. 9—15.

1877. — uNpDuLATO-PLIcATUS, C. Schliiter. Paleontographica, vol.
xxiv, p. 270, pl. xxxviil,
fig. 1.
1878. — — C. Barrois. Ann. Soc. géol. du Nord,
vol. v, p. 475.
1894. — prarratus, K. Jimbo. Paleont. Abhandl., vol. vi, p. 48,
pl. viii, figs. 8—10.
1899. — Scumipti, Rk. Michael. Jahrb. d. k. preuss. geol. Landesanst.

fiir 1898, vol. xix, p. 162, figs. 1—4.

Description.—Shell ovate, much higher than long, very inequilateral; the early
part of the shell of small or moderate convexity, the later part only slightly convex
or nearly flat. Hinge-line forming more than a right angle with the anterior
margin. Umbones terminal, small, curved anteriorly.

Ornamentation consists of concentric and radial ribs; the former are more
distinct on the early part of the shell, the latter on the later part. The radial ribs
curve outwards from a line between the umbo and the postero-ventral extremity ;
they have rounded summits, and are separated by broad shallow interspaces ; a
tubercle or rounded elevation may be developed where the concentric ribs cross
the radial ribs.

Affinities—This species is closely allied to I. digitatus, Schliiter (non
Sowerby).

The fact that in some specimens the early part of the shell is ornamented with
concentric folds only, and the radial ribs appear on the later parts, suggests
that this species has been derived from one with concentric folds only, in a
manner similar to that in which J. suleatus has arisen from I. concentricus (see p.
268); the specimens at present available, however, do not enable us to trace the
origin of I. wadulato-plicatus, but it seems probable that it has descended from a
flat variety of I. inconstans.

Forms from Vancouver Island with a similar type of ornamentation have been

INOCERAMUS. 305

referred to I. wndulato-plicatus by Whiteaves,' but White* doubts the correctness
of the identification. J. diversus, Stoliczka,’ is another allied form.

Michael does not accept Schmidt’s and Schiliiter’s identification of the
specimens from Saghalien and North Germany with Rémer’s J. widulato-plicatus,
but regards them as belonging to a distinct species for which he proposes the
name I. Schividti. He, however, regards I. diversus, Stoliczka, as an example of

Fic. 61.

Fic. 60.—Inoceramus undulato-plicatus, Rom. Senonian, Haldon. British Museum, No. L17371. Flint
cast of part of right valve. Natural size.

Fie. 61.—Inoceramus undulato-plicatus, Rom. Senonian, Haldon. British Museum, No. L17369. x 2.

this species, consequently it was unnecessary to introduce a new name. The
English specimens show a good deal of variation, and after comparing them with
Romer’s and other figures I do not feel able to accept Michael’s view.
Type.—From the Chalk of Texas.
Distribution.—Senonian of Haldon.

1 «Geol. Surv. Canada, Mesoz. Foss.,’ vol. i (1879), p. 168, pl. xx, fig. 2, and I. digitatus (ibid.,
1903), p. 395; also ‘ Trans. Roy. Soc. Canada,’ ser. 2, vol. i (1895), p. 121.

2 «Bull. U.S. Geol. Surv.,’ no. 51 (1889), p. 37.

3 «Palwont. Indica, Cret. Fauna 8. India,’ vol. iii (1871), p. 407, pl. xxvii, fig. 6.

CRETACEOUS LAMELLIBRANCHIA.

Fic. 62.—Inoceramus undulato-plicatus var. digitatus, Schliit. Zone of Micraster cor-anguinum, Snowdown
Colliery Shaft, Nonington, near Dover. British Museum, No. L20S44 (discovered and presented by
3

Dr. Malcolm Bwrr). Cust of part of left valve. x 4.

INOCERAMUS. 307

INOCERAMUS UNDULATO-PLICATUS rar. piairares, Schliiter, 1877. Vext-fig. 62.

1875. Inocrramus pierratus, F. Schmidt. Mém. Acad. Imp. Sci. de St. Pétersb.,
ser. 7, vol. xix, no. 3, p. 25 (partim),

pl. vi, figs. 3, 5.

1877. _ —- C. Schliiter. Palwontographbica, vol. xxiv, p. 267,
pl. xxxvi.

1878. — — C. Barrois. Ann. Soc. gévl. du Nord, vol. vy,
p. 475.

1902. —- -- A. Wollemann. Wiimeburg. Kreide (Abhandl. d.

k. preuss. geol. Landesanst.,
N.F., 37), p. 70.

Remarls.—As was pointed out by Schiliiter, this form is very closely allied to, and
perhaps not separable from, /. wndulato-plicatus ; it differs from the latter mainly
in that the posterior ribs are stronger and fewer in number than the anterior ribs,
but the early parts of the shell are very similar in the two forms. Until more
specimens have been obtained the exact relationships of the two forms cannot be
determined, and for the present it seems best to regard J. digitatus of Schliter
(non Sowerby) as a variety of L. widuluto-plicatus.

Distribution —Zone of Micraster cor-anguinwm of Charlton, Snowdown Colliery
Shaft, Nonington near Dover, Preston near Faversham, and Salisbury. Zone of

Actinocamax quadratus of Salisbury.

Inoceramus Lamarck, Parkinson, 1819. Plate LIT, figs. 4—6; Plate LIII, figs:
1—7. Text-figs. 63—85.

1768. Osrreopinnites, J. H. I. Walch. Naturgeschichte d. Verstein., vol. ii,
p. 142, pl. p1**, figs. 1—5.
1819. Ivnoceramus Lamarcku, J. Parkinson. Trans. Geol. Soc., ser. 1, vol. v,
p. 55, pl. i, fig. 3.

1822. — Cuviert, J. Sowerby. Trans. Linn. Soc., vol. xiii, p. 453,
pl. xxv.
— --- Lamarck, G. Mantell. Foss. 8. Downs, p. 214, pl. xxvii,
fig. 1.
-- — Cuviert, Mantell. Ibid., p. 213, pl. xxvii, fig. 4, pl. xxviii,
figs. 1, 4.

— — Bronenrartt, Mantell. Ibid., p. 214, pl. xxvii, fig. 8.

_- o Wesstert, Mantell. Ibid., p. 216, pl. xxvii, fig. 2.

= —_ unpuLatus, Mantell. Ibid., p. 217, pl. xxvii, fig. 6.

— -- Latus, Muntell. Ibid., p. 216, pl. xxvii, fig. 10.

— Carinius Cuvrert, A. Brongniart. In Cuvier’s Ossemens Foss., vol. ii,
p. 601, pl. iv., fig. 10.

CRETACEOUS LAMELLIBRANCHIA.

Jnoceramus Cuvrert, J. de C. Sowerby. Min. Conch., vol.

CarinLus LAMARCKI, F’, Dujardin.

Ivnoceramus Bronentarti, W. Hisinger.

Inocrramus Broneniarti, F. Rimer.

Cuvier!, Dujardin.

Weide Beh apt
eccexhi, fig. 1.
Bronenrartti, Sowerly. Ibid., vol. v, p. 60, pl. cecexli, figs.
2,3.
Lamarcxil, A, Goldfuss. Petref. Germ., vol. ii, p. 114, pl.
exi, fig. 2.
Cuviert, Goldfuss. Ibid., vol. ii, p. 114, pl. exi, fig. 1.
Bronenrarrt, Goldfuss. Ibid., vol. ii, p. 115, pl. exi, fig. 3.
striatus, Goldfuss. Ibid., p. 115, pl. exii, fig. 2.
Mém. Soe. géol. de France, vol. ii,
p. 225.
Ibid., vol. ii, p. 225.
Lethea Suecica, p. 56, pl. xvii,
fig. 11.
Cuvirert, Hisinger. Ibil., p. 56, pl. xvii, fig. 10.
Lamarcxu, F. A. Rimer. Die Versteiu. d. nord - deutsch.
Kreidegeb., p. 62.
Ibid., p. 62.
Ibid., p. 61.
Tbid., p. 63, pl. viii, fig. 12.
Die Verstein. der bohm. Kreideformat.,
pt. 2, p. 25.
Ibid., pt. 2, p. 24.
Statist. eéol. min. de l’Aube, Atlas,
pl. iv, fig. 7.
Ibid., pl. iv, fig. 4.
Cuviert, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii,
p. 520.
Broneniartt, H. B. Geinitz. Das Quadersandst. oder Kreide-
geb. in Deutschland, p. 172.
Cuviert, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 250.
— R. Kner.

Cuvieki, Rimer.
Broneniartl, Rimer.
UNDULATUS, Rimer.

Cuvier, A. EH. Reuss.

Broneaniarti, Reuss.
Cuviert, A. Leymerie.

ANNULATUS, Leymerie.

Kreidemerg. v. Lemberg (Haidinger’s
Naturwiss. Abhandl., vol. i, pt. 2),
p- 28.

Lamarck, J. Morris. Cat. Brit. Foss., ed. 2, p. 169.

Cuviert, Morris. Ibid., p. 169 (partim).

Bronentartit, Morris. Ibid., p. 169.

unpuLAtus, Morris. Ibid., p. 170.

Wessreri, Morris. Ibid., p. 170.

Cuvier, A. v. Strombeck. Zeitschr. d. deutsch. geol. Gesell-

sch., vol. xv, p. 124.

Bronenrartt, Strombeck. Ibid., vol. xv, p. 121.

— R. Drescher. Thid., vol. xv, p. 352.
Lamarxi, H. Favre. Moll. Foss. de la Craie de Lemberg,
p. 134.

Geol. v. Oberschles., p. 316, pl.

xxxiv, fig. 13.

1881.

? 1883.

7 190%.

INOCERAMUS. 309

Inoceramus Bronenrartt, H. B. Geinitz. Das Elbthalgeb. in Sachsen

(Paleontographica, vol. xx,
pt. 2), p. 43, pl. xi, figs.
3—10, pl. xiii, fig. 3.

Cuvrert, Geinitz. Ibid., p. 48 (partim), pl. xiii, fig. 8.

Bronaniarrt, Geinitz. Neues Jahrb. fiir Min., etc., p. 10.

Cuviert, Geinitz. Ibid., p. 15.

Lamarck, Geinitz. Ibid., p. 18.

Larus, C. Déeocg. Assoc. Franc. Avane. Sci. (Lille, 1874),

p- 369.
Cuvrert, C. Schliiter. Paleontographica, vol. xxiv, p. 266.
Bronentartt, C. Schliiter. Tbid., vol. xxiv, p. 263.
-- A. Fritsch. Stud. im Gebiete der bohm. Kreide-
format., ii, Weissenberg. u. Mal-
nitz. Schicht., p. 130, fig. 111.
-— G. Behrens. Zeitschr. d. deutsch. geo]. Gesellsch.,
vol. xxx, p. 256.
unpuxnatus, (. Barrois. Ann. Soc. géol. du Nord, vol. v,
p- 407.

(Myrinires) propiematicus, R. Etheridge, in Penning and
Jukes-Browne, Geol. Cam-
bridge, p. 143, pl. iii, figs.
9, 10, 11.

Bronenrarnt, A. Fritsch. Stud. im Gebiete der bohm. Krei-

deformat., iii Iserschicht., p. 110,
fig. 80.
Cuviert, A. Peron. Hist. Terr. Craie S.E. Bassin Anglo-
Parisien, p. 156.

Bronenrarti, Peron. Ibid., p. 157.

unpuLatws, Peron. Ibid., p. 157.

Cuviert, A. Fritsch. Stud. im Gebiete der bohm. Kreide-

format., iv, Teplitz. Schicht., p. 82,
fig. 74.
Bronenrartt, Fritsch. Ibid., p. 81, fig. 72.
Cuvrert, E. Stolley. Die Kreide Schleswig-Holsteins (Mit-
theil. a. d. min. Institut Kiel, vol. i.),
p- 241.
Broneniart, R. Michael. Zeitschr. d. deutsch. geol. Gesell-
sch., vol. xlv, p. 242.
striatus, H. Woods. Quart. Journ. Geol. Soe., vol. liii, p. 381,
pl. xxvii, fig. 13.

Cuvrert, R. Leonhard. Paleontographica, vol. xliv, p. 49,

Bronenrartr, Leonhard. Ibid., vol. xliv, p. 47.

— J. Simionescu. Fauna Cret. Super. Urmis,
p. 27.

Cuvrert, Simioneseu. Ibid., p. 27, pl. ii, figs. 8, 9.

aff. Cuviert, H. Imkeller. Paleontographica, vol. xlviii,
p- 34.

41

310

CRETACEOUS LAMELLIBRANCHIA.

1901. Inocrramus Cuviert, F. Sturm. Jahrb. d. k. preuss. geol. Landesanst.,

1902.

1903.

1904.

fiir 1900, vol. xxi, p. 92, pl. x, fig. 1.
— A. Wollemann. Liineburg. Kreide (Abhandl. d. k.
preuss. geol. Landesanst.,N.F., 37),
p- 67.
Bronenrarti, Wollemann. Ibid., p. 66.
-- W. Petrascheck. Jahrb. d. k. geol. Reichsanst.,
vol. lii, p. 161.
Cuviert, Petrascheck. Ibid., p. 162.
tatus, EL. T. Newtcn and A. J. Jukes-Browne. In Julkes-
Browne, Cret. Rocks of Britain, vol. iii,
p. 448 (partin).
corpiFormis, C. Airaghi. Boll. Soc. geol. Italiana, vol. xxiii,
p- 189, pl. iv, figs. 6—9.
Cuviert, A. Stojanof. Ann. géo]. min. Russie, vol. x, p. 121.
_- J. Nowak. Bull. Internat. Acad. Sci. Cracovie, p. 875.
Ltatus, W. Rogala. Ibid. (1911), p. 172, pl. iv, figs. 9, 10.
Koreuert, H. Andert. Inoceramen d. Kreibitz-Zittauer Sand-
steingeb., p. 57, pl. v, fig. 6, pl. i, fig. 6.

Cuviert, S. Nilsson. Petrific. Suecana, p. 19.

—_ Catittus Bronentarti, Nilsson. Ibid., p. 19.
1832. Inocrramus unpuxatus, C. H. v. Zieten. Verstein. Wiirttembergs, p. 96,

1866.

pl. Ixxii, fig. 7.
Lamarcsrit, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii,
p. 518, pl. cecexii, figs. 1—3.

Cuvrert, J. Miller. Petref. der Aachen. Kreidef., pt. 1, p. 31.

Broneniarti, Miller. Tbid., pt. 1, p. 30.

Lamarcxit, J. de C. Suwerby. In F. Dizon, Geol. Sussex,
p: 355 (p.385, ed. 2), pl. xxviii,
fig. 29 (= I. inconstans).

Lamarck, K. A. Zittel. Bivalv.d. Gosaugeb. (Denkschr. d. k.

Akad. d. Wissensch. Wien, Math.-
nat. Cl., vol. xxiv), pt. 2, p. 99 [23],
pl. xv, fig. 6.
_— H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal-
sontographica, vol. xx, pt. 2),
p- 50, pl. xiv, fig. 1 (fig. 4=
savonicus, Petrascheck).

Cuvier, Geinitz. Ibid., p. 48, pl. xiii, figs. 6, 7.

sTRIATUS, Geinitz. Ibid., pt. 1, p. 210, pl. xlvi, figs. 9—13 ;

pt. 2, p. 41, pl. xiii, figs. 1, 2, 9, 10.

uNDULATUS, J. Simionescu. Fauna Cret. super. Urmis, p. 26,

pl. ii, fig. 2.
Bronenrarti, C. Aivaghi. Boll. Soe. geol. Italiana, vol. xxiii,
p- 192, pl. iv, figs. 3—5.
Cuviert, H. Andert. Inoceramen d. Kreibitz-Zittauer Sand-
steingeb., p. 44, pl. ii, fig. 2.

INOCERAMUS. 311

Description.—Shell inequivalve, very inequilateral, of slight, moderate or
considerable convexity, sometimes inflated. Height greater than length. Hinge-
line of variable length in proportion to the height of the shell, forming more than
a right-angle with the anterior margin. Umbones terminal, curved inwards and
more or less forwards; the left umbo more prominent than the right. Anterior
marginal part of valves flattened, more or less nearly perpendicular to the plane
of the valves, either limited by a sharp edge from the flanks or without a definite
boundary. Anterior ear developed in some flat varieties.

The concentric folds may be absent, indistinct, or moderately or strongly
developed, with the dorsal and ventral slopes similar or with the ventral slope
steeper than the dorsal. Usually the folds are regular, but are not continued on
to the posterior ear. The curvature of the folds is often nearly symmetrical ;
its convexity on the convex and on some of the flat forms is small, but is greater
on the flat forms with a relatively short hinge. The growth-lines are distinct
and variable in number, and are sinuous where they pass on to the posterior ear.

Remarks.—The forms included in this species show a great amount of
variation, and seem in that respect comparable with some species of Micraster and
Echinocorys. Several of the varieties have been described as distinct species, but
the study of a large series of specimens has shown so many intermediate forms
that one can only regard the varieties as modifications of a very plastic species.
The features in which variation is most marked are the convexity of the valves,
the number, strength, and.curvature of the concentric folds, the distance between
the growth-lines, the size and distinctness of the posterior ear, and the height of
the shell.

Some forms of this species are only slightly convex (Plate LIT, fig. 7, Text-
fies. 73—83), so that in large specimens considerable portions of the shell
approach flatness. In other forms the valves are moderately or considerably
convex, and sometimes inflated (Plate LII, figs. 4, 5, Text-figs. 63—68). The
amount of convexity may remain nearly uniform throughout the growth of the
shell, or the earlier part may be only slightly convex and the later part very
convex—in such cases the early part resembles the adult shell of the large flat
varieties (Figs. 64, 65). The two valves may be of nearly equal convexity (Plate
LIT, fig. 5), or the left valve may be very convex whilst the right valve is only
slightly convex (Plate LIT, fig. 6).

The concentric folds vary in strength, number, form, curvature and regularity.
In the majority of cases the folds are prominent and form strong ridges (Figs. 68,
69, 78, 82, 84), but they may become only gentle undulations (Figs. 74, 77, 81),
and are sometimes indistinct or absent (Figs. 73, 75, 76, 79). The dorsal and
ventral surfaces of the folds may slope equally, or the ventral slope may be
steeper than the dorsal, giving a step-like appearance. The crest of the fold is

paar
bo

CRETACEOUS LAMELLIBRANCHIA.

Fic. 63.—Inoceramus Lamarchi, Park. The type. Upper Chalk (probably zone of Micraster cor-anguinum),
near Dover. British Museum, No. L9801. Left valve and dorsal view. Part of the posterior ear is
concealed by flint. Natural size.

=

Fic. 64—Inoceramus Lamarcki, Park. Anterior view of specimen shown in Fig. 65. x

a

Ble}

INOCERAMUS.

Fig. 65.

~

—

er planus), Swaffham, Norfolk.

Fie. 65.—Inoceramus Lamarcki, Park. Upper Chalk (probably zone of Holast
Norwich Museum, No, 3354. Right valve. x 3
Fig. 67.—Inoceramus Lamarcki, Park. Upper Chalk (zone of Holaster planus), Newmarket. Sedgwick
Natural size.

Museum, Cambridge. Right valve.

The original of I. Lamarcki, Mantell, ‘ Foss. S. Downs,’ p. 214,

Middle Chalk (probably zone of Terebratulina lata), near Lewes (probably Malling).
Natural size.

Fic. 66.—Inoceramus Lamarcki, Park.
Right valve.

pl. xxvii, fig. 1.
British Museum, No. 4753.

514. CRETACEOUS LAMELLIBRANCHIA.

Fic. 68.—Inoceramus Lamarcki, Park. The type of I. Brongniarti, Mantell, ‘Foss. S. Downs,’ p. 214,
pl. xxvii, fig.8. From Lewes or Brighton, probably zone of Micraster cor-anguinum. British Museum,
No. 4751. Left valve and dorsal view. Natural size.

ae Pat . oH
Fie. 69.—Inoceramus Lamarcki, Park. The original of I. Cuvieri, Mantell, ‘ Foss. S$. Downs, p. 213,
pl. xxviii, fig. 4. Zone of Micraster cor-anguinum, Southeram. British Museum, No. L22094. x j.

INOCERAMUS.

Fic. 71.

Q1T5
old

Fic. 70.—Inoceramus Lamarcki, Park. The original of I. Brongniarti, Sowerby, ‘Min. Conch.,’ vol. v,

p. 60, pl. cecexli, fig. 2. Chalk. Locality and horizon unknown. British Museum, No. 43265.
Right valve. Natural size.

Fig. 71.—Inoceramus Lamarcki var. Websteri, Mant. The type of I. Websteri, Mantell, ‘ Foss. S. Downs,’
p. 216, pl. xxvii, fig. 2. Upper Chalk (probably zone of Micraster cor-testudinarium), South Street,

Lewes. British Museum, No. 4759. Left valve. Natural size.
Fia. 73.

Fic. 72.—Inoceramus Lamarcki var. Websteri, Mant. Upper Chalk, Swaffham, Norfolk. Norwich Museum,
No. 3298. Left valve and anterior view. Natural size.

Fic. 73.—Inoceramus Lamarcki var. Cuvieri, Sow. The type of Inoceramus Cuvieri, Sowerby, ‘ Trans. Linn.
Soe.,’ vol. xiii (1822), p. 453, pl. xxv, figs. 2, 3, and ‘ Min. Conch.,’ vol. v (1823), p. 59, pl. eccexli, fig. 1.
Middle Chalk (zone of Terebratulina lata), Royston. British Museum, No. 43264. Left valve.
Natural size.

316 CRETACEOUS LAMELLIBRANCHIA.

usually rounded, but in one variety (Websteri, Mantell, Plate LIII, figs. 1, 2,
Text-figs. 71, 72) it possesses a sharp edge. When the folds are absent the
growth-rings become more regular. The curvature of the folds is usually small
in the more convex specimens, but often greater in the less convex forms. The
curvature is often nearly symmetrical, but when the posterior ear is indistinctly
limited it tends to become unsymmetrical.

The degree of development of the posterior ear varies considerably. In some
forms it is only indistinctly limited (Plate LIII, fig. 7, Text-fig. 68), and then the

Fia. 74.—Inoceramus Lamarcki var. Cuvieri, Sow. Upper Chalk (zone of Micraster cor-anguinuwm), Camp
Hill, near Salisbury. Dr. Blackmore’s Collection. Portion of a large left valve ; posterior and ventral
parts missing, x {.

folds and growth-lines are continued with but little alteration in curvature on to
the ear. In other cases the ear is larger and more or less distinctly limited from
the rest of the valve (Plate LII, fig. 4, Text-figs. 63, 65, 66, 79, 81, 82); in such
cases the folds and growth-lines bend inwards at the limit, and the umbonal part
of the valve is often narrower and more acute. In a few large, flat forms, an
anterior ear is developed (Fig. 74).

The anterior flattened area varies in size and in the distinctness of its
boundary. It may be nearly perpendicular to the plane between the valves
(Fig. 81), or may be slightly concave (Figs. 63, 66, 79), or slope outwards (Figs.

INOCERAMUS. 317

74,79). In some varieties the area forms a sharp edge with the sides of the
valve (Fig. 81), in others the boundary is curved and the limit of the area is
indistinct (Fig. 85).

In the type of Z. Lamarcki, Parkinson (Fig. 63), the shell is inflated, and the
posterior ear well developed and sharply limited. In forms like I. Brongniarti
Sowerby (Fig. 70, Pl. LIT, fig. 4), the posterior ear is also well developed, but

o

Fie. 75.—Inoceramus Lamarcki var. Cuvieri, Sow. Upper Chalk, Southeram, Lewes. Brighton Museum,
No. 340. Portion of a left valve resembling the type of I. latus, Mant. x {.

not so sharply limited as in the type of J. Lamarcki. Mantell’s I. Lamarchki
(Fig. 66) is similar to I. Brongniarti, Sowerby, but has less prominent folds and
amore concave anterior border. J. Brougniarti, Sowerby, passes gradually into
forms like the type of [. Brongiiarti, Mantell (Fig. 68), in which the limit of the
posterior ear is somewhat indistinct. Other varieties possess similar strong folds
but. have less convex' valves (as in J. Cuvieri, Mantell, Figs. 69, 84), and these

1 In some cases the smaller convexity may be due to pressure which gradually changed the
shape of the shell. When no fractures are seen, flattening appears to be indicated in some cases by
the growth-lines cutting the folds obliquely.

42

pass into forms wit

18 CRETACEOUS LAMELLIBRANCHIA.

h indistinct folds like the type of J. Curieri, Sowerby (Fig.

73), and in some cases the folds disappear altogether.
i gs

], ‘Foss. 8. Downs,’
British Museum, No. 5848. Left valve.

Fig. 76.—Inoceramus Lamarcki var. Cuvieri, Sow. The type of Inoceramus latus, Mantel

p. 216, pl. xxvii, fig. 10. Upper Chalk, near Brighton.
Natural size.
L. Websteri, Mantell (Figs. 71, 72), has the posterior ear fairly well developed,
and resembles I. Brongniarti of Mantell; it is

but not distinctly limited,
but forms

characterised by the thinness of the shell and the sharp ridge-like folds,

INOCERAMUS. 319

intermediate between this type and those with rounded folds occur. It may
be convenient to adopt for this variety the name [. Lamarchki var. Websteri. It
appears to occur mainly in the zone of Micraster cor-testudinarium.

1. undulatus, Mantell (Pl. LUT, fig. 3), resembles small forms of L. Brongiiarti,
Sowerby, but the folds are much smaller, more numerous, and less conspicuous,
and the shel! is thicker than usual.

Fic. 77.—Inoceramus Lamarcki var. Cuvieri, Sow. Upper Chalk (zone of Holaster planus), Swaffham,
Norfolk. Norwich Museum. Left valve. x %.
Some small forms (PI. LIIT, figs. 4—6), found in the Middle Chalk and in
+} o )

the zone of Holaster planus, which may be named I. Lamarecki var. apicalis,’ have
nearly equal valves, more prominent and more distinctly incurved umbones, with
the-folds indistinct or absent, but these forms pass into others with distinct folds.
In some of these small forins the umbo is curved anteriorly (Plate LIII, fig. +).

' An example of this from the Chalk Rock was figured in the ‘ Quart. Journ. Geol. Soe.,’ vol. lili
(1897), p. 381, pl. xxvii, fig. 15.

320 CRETACEOUS LAMELLIBRANCHIA.

I. latus, Mantell (Fig. 76) is a large, slightly convex form in which the folds

have almost disappeared. In the type (Fig. 76) the postero-dorsal part of
the valve is missing, so that in Mantell’s figure the umbonal part of the valve
appears to be more acute than it really is (compare Fig. 75).

I. Cuvieri, Sowerby (Fig. 73) is only slightly convex, with indistinct folds, and
is often of large size. The angle formed by the anterior margin and the hinge-

line is rather larger than usual, and an anterior ear may be developed ; other forms

Fic, 78.—Inoceramus Lamarcki var, Cuvieri, Sow. Upper Chalk, Lewes. Sedgwick Museum, Cambridge.
Right valve. Natural size.
are similar (Fig. 79), but have a smaller angle between the anterior margin and
the hinge, and these pass into forms with more distinct and eventually with
strong folds (Figs. 77, 78, 82). The varieties similar in form to Sowerby’s type,
but with or without folds, may be termed J. Lamarchi var. Cuvieri (Plate LIII,
fig. 7, Text-figs. 73—84). The hinge in large specimens of this variety (Fig. 80)
is of great thickness, and portions of it are often found separately. It is thickest
near the umbo, and becomes thinner towards the posterior end. The ligament
pits are numerous, shallow, and two, three, or more times higher than long,

INOCERAMUS. 321

Fic. 79.—Inoceramus Lamarcki var. Cuvieri, Sow. Zone of Holaster planus, Borstal. Mr. Dibley’s Collee-
tion. Right valve and anterior view. ~ Z.

Hi

Bev c see sn

§ Sse eSece
Cer Sas pegged =e

Fig. 80.—Inoceramus Lamarcki var. Cuvieri, Sow. Zone of Terebratulina lata, Royston. Sedgwick Museum,
Cambridge. Portion of left hinge. Natural size.

322 CRETACEOUS LAMELLIBRANCHIA.

reaching their maximum height not far from the umbo. The variety Curieri
ranges from the zone of J'erebratulina lata to the zone of Micraster cor-angquinun.

I, Muntell’, de Mercey,' from the zone of Micraster cor-anguinum, appears to
be a large form of J. Lamareki var. Cuvieri, in which an anterior ear is developed ;
it is similar to a specimen (Fig. 74) obtained by Dr. Blackmore from the zone of
Micraster cor-anguinum of Camp Hill near Salisbury.

Fic. $1.—Inoceramus Lamareki var. Cuvieri, Sow. Zone of Terebratulina luta, Blue Bell Hill, Burham.

Mr. Dibley’s Collection. Left valve with posterior part missing ; anterior view of the same valve. x §.

I. percostatus, Miiller* (especially the example figured by Petrascheck*), seems
to be closely allied to I, Lamarchi var. Webster’.

Types.—l. Lamareki, Parkinson (Fig. 63), from near Dover (probably zone of

!«Mém. Soc. Linn. Nord de la France,’ vol. iv (1877), p. 324. pls. i, ii. Barrois, ‘Ann. Soe.
e¢ol. Nord,’ vol. vi (1879), p. 454, pl. iv.

2 «Jahrb. d. k. preuss. geo), Landesanst. u. Bergakad. fiir 1887’ (1888), p. 413, pl. xvii, fig. 3.

3 «Jahrb. d. k. k. geo, Reichsanst.,’ vol. lvi (1906), p. 163, fig. 2. Also I. Glatziw and I. Kleini,
Andert, ‘Inoceramen d. Kreibitz-Zittauer Sandsteingeb.’ (1911), pp. 48, 52, pl. i, fig. 3, pl. ii, fig. 8.

INOCERAMUS.

oy)
bo
oo

Micraster cor-anguinum) ; in the British Museum, No. L980]. This specimen was
first recognised as the original of Parkinson’s figure by Mr. C. D. Sherborn.

Fig. 82.—Inoceramus Lamarcki var. Cuvieri,Sow. Chalk; locality and horizon unknown. British Museum,
No. L23909. Right valve. x }.

I. .Cuvieri, Sowerby (Fig. 73), from the Middle Chalk of Royston (zone of
Terebratulina lata); in the British Museum, No. 45264.

I, Lamareki, Mantell (Fig. 66), from the Middle Chalk near Lewes (probably
from Malling, zone of T'erebratulina lata) ; in the British Museum, No. 4753,

j24, CRETACEOUS LAMELLIBRANCHIA.

I. Cuvieri, Mantell (Figs. 69, 84), both from the zone of Micraster cor-anguinwin
of Southeram ; in the British Museum, Nos. 5845, L22094.
I. Brougniarti, Mantell (Fig. 68), from Lewes or Brighton (probably zone of

Micraster cor-anguinumn) ; in the British Museum, No. 4751.

Fic. 83.—Anterior view of specimen shown in Fig. 82. x }.

I. Websteri, Mantell (Fig. 71), from South Street [= Southeram], Lewes
(probably zone of Micraster cor-testudinarium) ; in the British Museum, No. 4759.

I. undulatus, Mantell (Plate LIIT, fig. 5), from Southeram, Lewes (probably
zone of Holaster planus) ; in the British Museum, No. 4767.

INOCERAMUS. 3

Fie. 84.—Inoceramus Lamarcki var. Cuvieri, Sow. The original of I. Cuvieri, Mantell, ‘ Foss. S. Downs,’ p. 213,
pl. xxviii, fig. 1. Zone of Micraster cor-anguinum of Southeram. British Museum, No. 5845. x 4.

Fic. 85.—Inoceramus Lamarcki, Park. Upper Chalk (? zone of Holaster planus), locality unknown.
Museum of Practical Geology, No. 21237. Variety with concave anterior area. Right valve and
anterior view. x j.

2)

326

CRETACEOUS LAMELLIBRANCHIA.

Fic. 86.—Imocevamus. A variety connecting I. Lamarcki with T. involutus. Upper Chalk
Sedgwick Museum. Right valve displaced. Posterior view. x .

Fie. 87.—Anterior view of specimen shown in Fig. 86. Natural size.

; probably Kent.

INOCERAMUS. 327

T.latus, Mantell (Fig. 76), from the Upper Chalk near Brighton ; in the British
Museum, No. 5848.

I. Brongniarti, Sowerby, 1823 (Fig. 70). Locality and horizon unknown ; in
the British Museum, No. 43265.

The small specimens from the zone of Rhynchonella Cuvieri near Cambridge,
figured by Etheridge as Inoceramus problematicus, are in the Museum of Practical
Geology (Nos. 21230—-21232).

Distribution. —I. Lamarcki ranges from the zone of Rhynchonella Cuvieri to the
zone of Micraster cor-anguinuin.'

Zone of Rhynchonella Cuvier’: St. Catherine’s Hill (Winchester), the Isle of
Wight, Cuxton, Burham, Dunton Green, the Sussex coast, Dover, Hitchin, Foul-
bourn near Cambridge, the Yorkshire coast.

Zone of Terebratulina lata : Hooken (South Deyon), the Isle of Wight, Cuxton,
Blue Bell Hill (Burham), Dunton Green, Kenley, Westerham, Lewes, the Sussex
coast, Holborough near Rochester, Dover, Guilford Colliery (Coldred near Dover),
Hitchin, Royston, the Yorkshire coast.

Zone of Holaster planus: The South Devon and Dorset coasts, the Isle
of Wight, Winchester, Homington (Salisbury), Cuxton, Borstal, Whyteleaf
(Warlingham), the Sussex coast, Dover, Newmarket, Swaffham (Norfolk),
Westacre, Narborough, the Yorkshire coast. Chalk Rock of Cuckhamsley.

Zone of Micraster cor-testudinarium : The South Devon and Dorset coasts, the
Isle of Wight, Borstal Fort, Borstal Manor pit, Chatham, Lewes, the Sussex coast,
Dover, Wharram Percy, the Yorkshire coast.

Zone of Micraster cor-anguinum: The Dorset coast, the Isle of Wight, Camp
Hill (Salisbury), Micheldever, Harefield, Southeram, the Sussex coast, St.
Margaret’s, Thanet, the Yorkshire coast.

Senonian of Haldon.

Inoceramus INvoLuTUs, Sowerby, 1828. 'Text-figs. 88—9-4.

1828. Inocrramus 1Nnvo.utus, J. de C. Sowerby. Min. Conch., vol. vi, p. 160,
pl. dlxxxiii, figs. 1—3.

1841. ~- -- FA. Riimer. Die Verstein. d. nord-deutsch.
Kreidegeb., p. 61.

1846. -- — A. dOrbigny. Pal. Frang. Terr. Crét., vol. iti,
p. 520, pl. cecexiii, figs. 1—3.

— —- Lamarcsu, d' Orbigny. Ibid., p. 518, pl. cecexii.

1850. -- tinvoLutus, d Orbiqny. Prodr. de Pal., vol. ii, p. 250.

1 Some authors have recorded this species from the zones of Marsupites testudinarius, Actinocamas

quadratus and Belemnitella mucronata, but I have not sufficient evidence to confirm these records.

328 CRETACEOUS LAMELLIBRANCHIA.

1850. Inoceramus tnvouurtus, J. de C. Sowerby, in F. Dixon. Geol. Sussex, p.
355 (p. 386, ed. 2), pl. xxviii, fig. 32.
1854. -- —- J. Morris. Cat. Brit. Foss., ed. 2, p. 169.
1863. — “= A.v. Strombeck. Zeitschr. 4. deutsch. geol.
Gesellsch., vol. xv, p. 127.
1871. — (VoLvicERAMUs) InvoLutTUus, F. Stoliczka. Paleont. Indica,
Cret. Fauna 8. India, vol.
iii, pp. 394, 401.

1875. — tnvoLutus, C. Décocg. Assoc. Frane. Avane. Sci. (Hille,
1874), p. 367.
1876. + oo D. Brauns. Zeitschr. f. d. gesammt. Naturwiss.,
vol. xlvi, p. 379.
1877. — — C. Schliiter. Paleeontographica, vol. xxiv, p. 272.
1878. — — C. Barrois. Aun. Soc. géol. du Nord, vol. v,
p- 475.
1888. — (Voxnviceramus) tnvo.utus, G. Miller. Jahrb. d.k. preuss.
geol. Landesanst. fiir 1887, p. 411,
pl. xvi, figs. 3, 4.
—- -— InvoLutus, A. Peron. Hist. Terr. Craie 8.E. du Bassin
Anglo-Parisien, p. 157.
1901. -- — F. Sturm. Jahrb. d. k. preuss. geol. Landesanst.
fiir 1900, vol. xxi, p. 91, pl. ix, fig. 4.
1902. — -— A. Wollemann. Liineburg. Kreide (Abhandl. d.
k. preuss. geol. Landesanst.
N.F., 37), p. 68, pl. i, fig. 4;
pl. ui, figs. 7, 8.
1906. — — G. Smolenski. Bull. Intern. Acad. Sci. Cracovie,
p: 721.
1909. — — J. Nowak. Ibid., p. 874, pl. xlvi, figs. 4, 5.
1910. — — J. Bohm. Centralbl. fiir Min., ete., p. 741.

Description.

Shell very inequivalve and very inequilateral. Right valve oyal
or semi-oval in outline ; usually slightly convex, but sometimes either more convex
or nearly flat, with the marginal part in old specimens forming an obtuse angle
with the earlier part. Length greater than height. Anterior and ventral margins
rounded ; posterior margin forming usually an obtuse angle but sometimes nearly
a right angle with the hinge. Umbo usually inconspicuous, at or near the
anterior end of the hinge-line. Hinge-line equals about three-quarters of the
length of the valve. Postero-dorsal marginal part convex near the hinge and
separated by a sharp furrow from the remainder of the valve. Ornamentation
consists of strong, somewhat irregular concentric folds, with an unsymmetrical
curvature ; the folds are separated by broad, concave interspaces. In casts of this
valve, and sometimes in the shell itself, radial markings are seen in the concave
interspaces.

Left valve much larger than the right, inflated, more or less considerably

c

INOCERAMUS. 329

Fic. 88.—Inoceramus involutus, Sow. Upper Chalk, locality unknown. The type. British Museum, No.
43268. Left valve. Natural size.

Fic. 89.—Inoceramus involutus, Sow. The original of the specimen figured in Dixon’s ‘Geol. Sussex,’ pl
xxvili, fig.32. Upper Chalk, Charing. Flint cast. British Museum, No. L83. Natural size.

330 CRETACEOUS LAMELLIBRANCHIA.

Fia. 90.—Inoceramus involutus, Sow. Upper Chalk, probably Kent. British Museum, No. L4917. Posterior
view. Umbonal part of left valve missing. Natural size.

ia. 91.—Anterior view of specimen shown in Fig. 90. Natural size.

INOCERAMUS. BF

Oy
—

spiral; with a very large umbo near the anterior end, curved inwards and
forwards. Surface nearly smooth, except for the presence of growth-lines.

The hinge (Fig. 94) curves at either end; it is thinnest near the umbo and
becomes thicker towards the posterior end. The ligament-pits are deep, almost
square, but sometimes oblong, and increase in height from the umbo posteriorly.

Fie. 92.—Right valve and part of left valve of specimen shown in Figs. 90, 91.

Affinities. —I. involutus is the type of‘the genus or sub-genus Volviceramus of
Stoliczka. In general appearance this differs considerably from other species of
Inoceramus, so that its separation as a distinct genus or sub-genus seems at first
sight quite justifiable; but the study of a large number of specimens of I. involutus
and I. Lamarcki shows that these two species are very closely allied, and that the
former has almost certainly descended from the latter. Such being the case it
follows that these two species are more nearly related to one another than are

352 CRETACEOUS LAMELLIBRANCHIA.

several species which are placed by all writers in the genus Jioceraimus. In this
respect Volriceramus is exactly comparable with Actinoceramus (p. 268).

A fairly complete passage can be traced from I. Lamareki to I. involutus. In
some forms of I. Lamarchi the valves become more unequal than usual, the left

Fic. 93.—Inoceramus involutus, Sow. Upper Chalk, locality unknown. British Museum, No. L21005.
Anterior view of left valve. x %.

valve being relatively larger and with less distinct folds, and the right relatively
less convex and its anterior area slightly concave (Fig. 85). These are connected
with some varieties of J. involutus by intermediate forms (Figs. 86, 87) m which
the left valve possesses nearly all the characters of I. involutus but is less curved
and possesses a concaye anterior area, whilst on the right valve the folds are
almost as prominent as in J, involutus, but the flattened or concave anterior area

INOCERAMUS. 333
and a relatively short hinge are still retained, and the right valve is still convex

and has a concave anterior area. A variety of J. involutus links such intermediate

forms with typical examples of involutus; in that variety the right valve is rather
more convex than in typical forms, the left valve is not so distinctly spiral, some
trace of the anterior flattened or concave area is still retained, and the hinge-line
is rather shorter relatively.

——

"

Fic. 94.—Inocerumus involutus, Sow. Upper figure :

Zone of Micraster cor-anguinum, Gravesend. Sedgwick
Museum, Cambridge.

Right valve with marginal growth round the hinge. x {.
Lower figure: Hinge of right valve ; Upper Chalk, Norfolk. Norwich Museum, No. 3355. The anterior
part of the hinge is partly concealed by the marginal growth of the shell. x §.

I. wmbonatus, Meek and Hayden,' from Fort Benton, Missouri, is, as stated by
Meek, very closely allied to, and perhaps identical with, /. imvolutus.

Another
related form is J. ewogyroides, Meek and Hayden.”

Both are regarded as synonyms

1 ‘Invert. Cret. and Tert. Foss. U. Missouri’ (1876), p. 44, pl. iii, fig. 1; pl. iv, figs. 1, 2.
2 Tbid., p. 46, pl. v, fig. 3.

44

334. CRETACEOUS LAMELLIBRANCHIA.

of I. involutus by Barrois. I. Koeneni, Miiller,! is probably a variety of
I. involutus in which the right valve is more convex and its umbo more prominent
than usual.

The right valve of the specimen figured by d’Orbigny (1846, pl. cecexn,
figs. 1, 2) as I. Lamarcki is an example of J. involutus; but the left valve (fig. 3),
if it belongs to the same individual, is probably incorrectly drawn.

Remarks.—Examples of this species often reach a large size, and in such cases
the hinge (Fig. 94) may attain a considerable thickness, but portions of it are
not often found separately. In old specimens the marginal part of the right
valve grows obliquely or almost at right angles to the earlier part, and the folds
become indistinct or disappear altogether; and in the right valve this marginal
growth sometimes occurs along the hinge, owing no doubt to the increase in size of
the left valve in which it then fits like an operculum (Fig. 94). The length varies
in proportion to the height, so that in some forms the right valve becomes nearly
circular.

Types.—The type (Fig. 88) is in the British Museum, No. 45268 ; its locality is
unknown. The specimen figured in Dixon’s ‘ Geology of Sussex’ (Fig. 89) is also
in the British Museum, No. L83; it is a flint cast and came from the Upper Chalk
of Charing.

Distribution.—I. involutus is found in the zone of Micraster cor-testudinarium
and the lower part of the zone of M. cor-anguinuwm, bemg particularly common at
the latter horizon.’

Zone of M. cor-testudinarium: Chatham, Dover, and Seaford, Sussex.

Zone of M. cor-anguinum: Winchester, Quidhampton, Mapledurham, Thanet,
St. Margaret’s, Guilford Colliery (Coldred near Dover), the Sussex coast, Lewes,
Haling pit (South Croydon), Strood, New Brompton (Chatham), Gravesend,
Harefield near Rickmansworth, Bury St. Edmunds, Saham Toney, Thetford,
Brancaster, and other places in Norfolk. Between the zones of M. cor-

testudinarium and M. cor-anguinwm near Beverley, Yorkshire. Senonian of
Haldon.

InoceraAmus corpirormis, Sowerby, 1823. Plate LIII, fig. 8. Plate LIV, figs. 2—4.

1823. Inoceramus corpirormis, J. de C. Sowerby. Min. Conch., vol. v, p. 61.
pl. cecexl.

1836, ~: — A. Goldfuss. Petref. Germ., vol. ui, p. 113,

pl. ex, fig. 6b (not 6a).

‘Jahrb. d. k. preuss. geol. Landesanst.’ fiir 1887 (1888), p. 412, pl. xvii, fig. 1.
2 This species has been recorded by Griffith and Brydone from the Uintacrinus band of the

Marsupites zone of Ropley, Hampshire; and by Barrois from the zone of Actinocamax quadratus of
Newhaven.

INOCERAMUS. 335

1854. INocrramus corpirormis, J. Morris. Cat. Brit. Foss., ed. 2, p. 169.

1897. ~- R. Leonhard. Paleontographica, vol. xliv, p. 48.
1898. - Hagnvernt, G. Miller. Mollusk. Untersen. vy. Braunschweig

u. Ilsede (Abhandl. d. k. preuss.
geol. Landesanst., N.F., 25), p. 41,
pl. v, fig. 7; pl. vi, figs. 1, 2.
y IGy tle — corpirormis, W. Rogala. Bull. Internat. Acad. Sci. Cracovie,
p. 170, pl. iv, fig. 2.

Non 1904. — — C. Airaghi. Boll. Soe. geol. Italiana, vol. xxiii,
p. 189, pl. iv, figs. 6—9.

Description.—Shell inflated, equivalve, very inequilateral, rounded. Anterior
margin more or less nearly straight or undulating, but rounded in large specimens.
Ventral and posterior margins more or less sinuous. Anterior part of valves
more or less flattened and often nearly perpendicular to the plane between the
valves. Postero-dorsal part of valves much compressed and usually wing-like.
Hinge equal to more than half the height of the shell. Umbones terminal, large,
prominent, curved inwards and forwards. <A broad, shallow sulcus extends from
behind the umbo to the postero-ventral extremity and separates two broad,
rounded ridges. A similar sulcus may extend from the front of the umbo to the
opposite ventral margin.

Ornamentation consists of broad, rounded, concentric folds, which bend
upwards where they cross the two radial sulci. The folds become less distinct
on the anterior and postero-dorsal parts than on the sides of the shell. Numerous
close-set growth-lines are present.

Affinities.— I. Haenleini, Miller,’ from the lower part of the Lower Senonian of
Brunswick and Ilsede, seems to be hardly distinct from J. cordiformis. The
smaller English specimens agree very closely with one of the examples figured by
Miler (pl. v, fig. 7).

I. cordiformis resembles some of the more convex forms of J. Lamarcki,
Parkinson, from which it is distinguished by the equal size of the valves and the
presence of radial sulci. The specimen, figured (Pl. LIV, fig. 1), connects this
species with I. Lamarehi.

Remarks.—Goldfuss’ fig. 6b is a copy of Sowerby’s figure; his fig. 6u is the
type of I. savonicus, Petrascheck.

Type.—In the British Museum, No. 43277, from the Upper Chalk (zone of
Micraster cor-anguinum) of Gravesend (P1. LIII, fig. 8).

Distribution —Zone of Micraster cor-testudinarium of Clanfield (Hampshire),
and Wharram Percy (Yorkshire). Zone of Micraster cor-anguinum of Gravesend,
Micheldever, and Porton. Uintacrinus band of Salisbury. Senonian of Haldon.

' *Mollusk. Untersen, v. Braunschweig u. Ilsede’ (1898), p. 41, pl. v, fig. 7; pl. vi, figs. 1, 2.

336 CRETACEOUS LAMELLIBRANCHIA.

INOCERAMUS COSTELLATUS, sp. nov. Plate LIV, figs. 5—7.

1897. Inocrramus, sp., H. Woods. Quart. Journ. Geol. Soc., vol. lili, p. 381,
pl. xxvii, figs. 14—17.

Description.—Shell small, very inequilateral, rather higher than long, of
moderate convexity—the greatest convexity being between the umbones and the
postero-ventral extremity. Umbones terminal. Hinge equal to about three-
quarters of the length of the shell, and forming more than a right angle with the
anterior margin. Anterior margin moderately convex, ventral margin very
convex, posterior margin slightly convex.

Right valve with a small, pointed, slightly curved umbo. Posterior and postero-
dorsal parts of the valve flattened. A small, flattened antero-dorsal area is nearly
perpendicular to the plane of the valves.

Left valve more convex than the right; postero-dorsal part compressed, but
not forming a definite ear. Umbo narrow, pointed, curved inwards, larger and
more prominent than the umbo of the right valve. Antero-dorsal area larger
than on the right valve.

Concentric ribs narrow, sharp, usually widely separated; imterspaces broad
and shallow. The curvature of the ribs is very unsymmetrical; the ventral part
is very convex, the posterior part only shehtly convex.

Remarks.—This species is fairly common in the Chalk Rock. All the speci-
mens seen are casts. Some examples, which appear to be a variety of this species,

have small ribs of uniform size.

Affinities —This species appears to be related to some forms of I. Lamarcli,
Parkinson, but the left umbo is narrower, more pointed, and less curved; the line
of greatest convexity is more oblique to the hinge-line, and the posterior and
postero-dorsal parts of the valves are more compressed.!

Type-—From the Chalk Rock of Cuckhamsley, in the Sedgwick Museum,
Cambridge.

Distribution—Chalk Rock of Dover, Guilford Colliery (Coldred near Dover),
the Sussex Coast, south-east of Calstone Willington, Cuckhamsley, Blount’s Farm
near Marlow, Luton, Wallington near Baldock, Barley near Royston, and
Underwood Hall near Dullingham. Zone of Holaster planus of South Devon, the
Dorset Coast, the Isle of Wight, Lichfield (Hants), Winchester, ete.”

’ Compare also I. undulatus, Rogala, ‘ Bull. Internat. Acad. Sci. Cracovie’ (1911), p. 171, pl. iv,
fig. 7, and I. Frechi, Andert, ‘Inoceramen d. Kreibitz-Zittauer Sandsteingeb.’ (1911), p. 51, pl. i,
fig. 8.

2 Recorded by Rowe from the zones of Terebratulina lata and Micraster cor-anguinum of Dover.

INOCERAMUS. 337

InoceraMus picitatus, Sowerby, 1829. 'Text-fig. 95.

1829. Inocreramus picrratus, J. de C. Sowerby. Min. Conch., vol. vi, p. 215,
pl. deiv, fig. 2.
1854. J. Morris. Cat. Brit. Foss., ed. 2, p. 169.
? 1875. - CU. Décocg. Assoc. Franc. Avane. Sci. (Lille,
1874), p. 368.

Remarl:s.—This species attains a large size, but is known only by small

Fig. 95.—Inoceramus digitutus, Sow. The type. From the Drift (derived from the Chalk). British
Museum, No. 48273. x j.

portions of the shell of which the exact horizon cannot be determined. The
ornamentation consists of broad, rounded, radial folds, which diverge very
gradually and are separated by broad rounded interspaces. Small concentric
ribs oceur, and at distant intervals, broad, gentle, concentric folds can be traced.
The form referred to I. digitatus by Schliiter differs from that species in having

338 CRETACEOUS LAMELLIBRANCHIA.

diverging and distinctly curved ribs. J. digitatus appears to be closely allied to
I. subcardissoides, Schiiiter.

T'ype.—From the Drift (derived from the Chalk); locality unknown. In the
British Museum, No. 43,273.

Distribution.—No undoubted specimens obtained directly from the Chalk have
been seen.

INOCERAMUS PINNIFORMIS, Willett, 1871. Text-fig. 96.

1871. Inoceramus pinnirormis, H. Willett. Cat. Cret. Foss., Brighton Mus.,
p- 40, no. 342,

Description.—Shell very large, much higher than long, of moderate convexity,
with a posterior wing-like part.

Ornamentation consists of broad, strong, widely separated concentric folds
which have a nearly symmetrical curvature; the ventral slopes of the folds are
rather steeper than the dorsal; in the interspaces are small (sometimes indistinct)
concentric folds, which give a more or less marked tuberculate character to the
radial ribs. The latter are rounded, rather numerous, sometimes partly or com-
pletely divided by a median furrow, and are continued on to the dorsal surfaces
of the strong concentric folds, but are absent or indistinct on the ventral surfaces.

Remarks.—A_ portion of a large Inoceramus named I. pinniformis by Willett
resembles I. subeardissoides, Schliiter,’ but differs from that species by the more
numerous radial ribs and the absence of a broad furrow extending from the umbo
in a postero-ventral direction.

Type.—In the Brighton Museum.

Distribution.—Upper Chalk (zone of Actinocamar quadratus) of Brighton, and
three miles east of Sledmere, Yorkshire.

1 « Paleontographica,’ vol. xxiv (1877), p. 271, pl. xxxvii; Barrois, ‘Ann. Soe. géol. Nord.,’
vol. v (1878), p. 474; Wollemann, ‘ Liineburg. Kreide’ (1902), p. 70; Wegner, ‘ Zeitschr. 4d.
deutsch. geol. Gesellsch.,’ vol. vii (1905), p. 169; I. Gosseleti, Décoeq, ‘ Assoc. Frane. Avance. Sci.,’
1874 (1875), p. 371.

INOCERAMUS.

Fig. 95.—Inoceramus pinniformis, Willett.

Upper Chalk (zone of Actinocamax quadratus), Brighton.

Brighton Museum, No. 342. Portion of right valve. x §.

340 CRETACEOUS LAMELLIBRANCHIA.

INocERAMUS CoRRUGATUS, sp. nov. Text-fig. 97.

Remarks.—This species is at present known only by a small portion of one
valve. It is of the same general type as I. digitatus, Sowerby, I. pinniformis,
Willett, and J. subecardissoides, Schliiter, but owing to the presence of broad,
strong radial folds the radial ribs are arranged in groups of four or five. The

Fia. 97.—Inoceramus corrugatus, sp. nov. Upper Chalk, Wouldham Cement Quarry, Grays. British
Museum, No. L22528 (discovered and presented by Col. C. E. Shepherd). Natural size.

concentric folds are strong and have a steep ventral, and a gentle dorsal slope.
The growth-lines are distinct and regular. J. corrugatus and the other species
mentioned may be compared with /. lezennensis, Décocq,’ which is of the same
type as I. Lamarcki but possesses two radial folds due to the presence of a medial
suleus.

Distribution—Upper Chalk, Wouldham Cement Company’s Quarry, Grays,
Essex.

1 Barrois, ‘ Ann. Soe. géol. du Nord,’ vol. vi (1879), p. 455, pl. 5, figs. 1, 2.

Palxontographical Society, 1912.

A MONOGRAPH

CRETACEOUS LAMELLIBRANCHIA

ENGLAND.

BY

HENRY WOODS, M.A.
UNIVERSITY LECTURER IN PALHOZOOLOGY, CAMBRIDGE

VOL. Hy (RAT xX:

OSTREIDA, RADIOLITIDA, ADDITIONS, DISTRIBUTION,
BIBLIOGRAPHY, INDEX.

Paces 341—473; Puiates LV—LXII.

LONDON:
PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY.
1913,

PRINTED BY ADLARD AND SON, LONDON AND DORKING,

OSTREID Ai. 341

Family—OSTREIDA, Lamarck.
[Omitted from Vol. I, p. 223.]

The great difficulties in the systematic study of the Ostreide have been
felt by nearly all writers,‘ and are due mainly to the extraordinary variation
in, the form of the shell. This variation has been brought about by changes in the
physical conditions of habitat, and particularly by differences in the character of the
surface to which the left valve is fixed; it is found that the mode of growth and
ultimate shape of the shell are determined mainly by the size, shape, and position
of the attached surface, so that commonly any one species shows an amazing variety
of forms which can, however, be linked together by large series of specimens. A
further difficulty in the systematic study of oysters is due to the fact that the shell
usually possesses little or no ornamentation.

Various generic or sub-generic divisions have been proposed for the Ostreide,
e. g. Ostrea, Lopha ( = Alectryonia), Arctostrea, Hxogyra, Amphidonta, Gryphea,
Pycnodonta, Gryphzostrea ; but it appears to me that the phylogenetic relationship
of the species of oysters is more complex than is represented by these divisions,
and that a natural grouping can only be established when more is known of the
evolution of the species. The forms with radial folds have usually been grouped
together under the name Alectryonia ; but there can be no doubt that such folds
have originated independently in more than one line of descent, and their presence
does not necessarily indicate close relationship. Thus, for example, Ostrea semi-
plana, which has been commonly referred to Alectryonia, appears to be more closely
allied to Ostrea vesicularis than to any species of Alectryonia. The Cretaceous
forms which have been referred to Gryphea clearly owe their grypheate character
to the small size of the attached surface,’ and can be traced into forms having the
characters of Ostrea. In studying the Upper Cretaceous oysters of Tunis, Peron *
has already noticed that some individuals of a species may present the characters
of Ostrea, whilst others are exogyriform or grypheate. In the Chalk of England
Ostrea semiplana is usually ostreiform, but occasionally, when the attached surface
is behind the umbo, the shell is at first exogyriform, but afterwards becomes
ostreiform.

1 See, for example, the remarks of Hill and Vaughan, “ Lower Cretaceous Grypheas of the Texas
Region” (‘Bull. U.S. Geol. Survey,’ No. 151, 1898), p. 24; and Peron, “ Descript. Brach., etc,
Terr. Crét. Tunisie” (1890—91), pp. 105—109.

2 See R. T. Jackson, ‘‘ Phylogeny of the Pelecypoda. The Aviculide and their Allies” (‘ Mem.
Boston Soc. Nat. Hist.,’ vol. iv, 1890), p. 317;' H. Douvillé, ‘ Bull. Soc. géol. France,’ ser. 4, vol. x
(1910), pp. 635, 642.

* Op cit., p. 107.

45

342 CRETACEOUS LAMELLIBRANCHIA.

In this work Hzogyra is retained as a genus since the species dealt with seem to
be genetically related, but it is probable that the exogyriform type has originated
independently in some earlier deposits. It is even possible that a few species
referred to Ostvea may have arisen from an exogyriform type by the increase in the
size of the attached surface, and the gradual loss of the spiral character of the
umbo.

In the Ostreidee, perhaps even more than in the case of Jnoceramus, the number
of figures which can be given is altogether insufficient to convey an adequate idea
of the great variability of the species. It is only by the study of very extensive
collections of specimens that one can hope to arrive at satisfactory conclusions.

Genus—Ostrea, Linneus, 1758.

(‘ Syst. Nat.,’ ed. 10, p. 696.)

OstreA pinuviANA, L. Text-figures 98-138.

1767. Osrrea piLuviaANA, Linneus. Syst. Nat., ed. 12, p. 1148.
1768. G. W. Knorr and J. FE. M. Walch. Recueil. Mon. Catastr. Pétrificat.,
vol. 11, p. 123, pl. D ii, figs. 5, 6.
1779. ‘Grypuitn,” B. Fawas-St.-Fond. Hist. nat. Mont. St. Pierre de Maes-
tricht, p. 151, pl. xxiv, figs. 1, 2.
1806. Osrrea pEctinATA, Lamarck. Ann. du Muséum, vol. viii, p. 165; vol. xiv,
1809, pl. xxiii, f. 1.
— — carinata, Lamarck. Ibid., vol. viii, p. 166.
1811. — rrons, J. Parkinson. Organic Remains, vol. iii, p. 217, pl. xv,
fig. 4.
1813. OsrracirEs pLicatTissimus, EH. 7. v. Schlotheim. In Leonhard’s Taschenb.
fiir Min., vol. vii, p. 112.
1819. Osrrea cotuBRrina, Lamarck. Anim. sans Vert., vol. vi, p. 216 (non
Goldfuss).
— — carinata, Lamarck. Ibid., p. 216.
= — opiLuviana, Lamarck. Ibid., p. 214.
1821. Osrracrres piLuvianus, G. Wahlenberg. FPetrific. Tellur, Suecane, p. 58.
1822. Osrrea cartnata, J. Sowerby. Min. Conch., vol. iv, p. 89, pl. ecclxv.
— — — G. B. Sowerby. Genera Recent and Foss. Shells, No.
vi, fig. 1.
— — serrata, G. Cuvier and A. Brongniart. In Cuvier’s Ossemens
Foss., vol. ii, pt. 2, pp. 251, 599, pl. iii, fig. 10.
— — carinata, Cuvier and Brongniart. Ibid. pp. 320, 599, pl. iii,
fig. 11.
1824. — macropTeRa, J, de C. Sowerby. Min. Conch., vol. v, p. 105, pl.
ececlxviii, figs. 2, 3.

1827.

1839.

OSTREA. 343

OstrEA piLuviaNna, S. Nilsson. Petrific. Suecana, p. 32, pl. vi, figs. 1, 2.
— — G. P. Deshayes. Hist. nat. Vers et Mollusques
(Encyel. méthod.), vol. iv, pl.
elxxxvii, figs. 1, 2; pl. clxxxviii,
figs. 1, 2.
— carrinata, Deshayes. Ibid., vol. ii, p. 301; Planches, vol. iv,
pl. elxxxvii, figs. 3—5.
— — A. Goldfuss. Petref. Germ., vol. ii, p. 9, pl. lxxiv,
fig. 6.
— prctinata, Goldfuss. Ibid., p. 9, pl. lxxiv, fig. 7.
— prrionora, Goldfuss. Ibid., p. 10, pl. Ixxiv, fig. 8.
— serrata, Goldfuss. Ibid., p. 10, pl. xxiv, fig. 9.
— pinuviana, Goldfuss. Ibid., p. 11, pl. lxxv, fig. 4.
ALECTRYONIA Derrancu, G. Fischer de Waldheim. Bull. Soc. Impér. Nat.
Moscou, vol. viii, p. 113, pl. iii.
“= Fervussact, Fischer de Waldheim. Ibid., p. 111, pl. iv.
OstREA RETUSA, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp-
338, 361, pl. xiv, fig. 4.
— opinuviana, W. Hisinger. Letheea Suecica, p. 49, pl. xiv, fig. 5.
— — FE. Dujardin. Mém. Soc. géol. de France, vol. ii,
p. 230.
— q@reGArRIA, fF. C. L. Koch and W. Dunker. Beitr. nord-deutsch.
Oolithgebild., p. 50,
pl. vi, fig. 2.
— REcTANGULARIS, F’. A. Rimer. Verstein. nord-deutsch. Oolithen-
geb., Nachtrag, p. 24, pl. xviii,
fig. 15.
— opinuviana?, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 1, p. 19.
— macropTreRa, Ff. A. Rimer. Die Verstein. d. nord-deutsch.
Kreidegeb., p. 45.
— carRInata, Romer. Ibid., p. 45.
— sERRATA, Rimer. Ibid., p. 45.
— OARINATA ETO. prionota, EH. Forbes. Quart. Journ. Geol. Soc.,
vol. i, p. 250.
— opinuvrana, H. B. Geinitz. Grundr. d. Verstein., p. 478.
— cartnata, A. HE. Reuss. Die Verstein. der bohm. Kreideformat.,
pt. 2, p. 38.
— DILuvIANA, Reuss. Ibid., p. 38, pl. xxx, figs. 16, 17; pl. xli, fig. 1;
pl. xlv, fig. 1. *
— carinata, A. Leymerie. Statist. géol. min. de l’Aube, Atlas, pl. v,
fig. 19.
— PES-LEONIS, H. Forbes. Trans. Geol. Soc., ser. 2, vol. vii, p. 156,
pl. xviii, fig. 5.
— macropTera, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 695,
pl. eceelxv.
— carinata, d’Orbigny. Ihbid., vol. iii, p. 714, pl. cecelxxiv, figs.
1—5. -

O44: CRETACEOUS LAMELLIBRANCHIA.

1847.

1854.

1855.
? 1859.

1863.

1868.

Osrrua FRONS, d’Orbigny. Ibid., vol. iii, p. 733, pl. eecclxxxiii.

Mritreriana, d’Orbigny. Ibid., p. 712, pl. eecelxxii, figs. 5—7.
piLuviaNa, d’Orbigny. Ibid., p. 728, pl. eccclxxx.
MACROPTERA, 7’. Brown. Ilustr. Foss. Conch. Gt. Brit. and Ireland,
p. 146, pl. lviii, figs. 1, 2.
caRINATA, Brown. Ibid., p. 146, pl. lix, fig. 6.
— A. d Orbigny. Prodr. de Pal., vol. ii, p. 170.
FRONS, d’Orbigny. Ibid., p. 255.
MACROPTERA, d’Orbigny. Ibid., pp. 84, 120.
RicorpEana, d’Orbigny. Ibid., p. 171.
Miuueriana, d’Orbigny. Tbid., p. 139.
DILUVIANA, d’Orbigny. Ibid., pp. 171, 198.
FRONS ET cARINATA, H. B. Geinitz. Das Quadersandst. oder
Kreidegeb. in Deutsch-
land, p. 196.
DILUVIANA, Geinitz. Ibid., p. 198.
carinata, F’. Rémer. Kreidebild. v. Texas, p. 75, pl. ix, fig. 5.
a H. G. Bronn. Uethea Geogn., ed. 3, vol. ii, p. 262,
pl.xxxii, fig. 2.
Mitteriana, F’. J. Pictet and W. Roux. Moll. Foss. Grés verts
de Geneve, p. 525,
pl. xlix, fig. 3.
MACROPTERA, J. Morris. Cat. Brit. Foss., ed. 2, p. 173.
FRrons, Morris. Ibid., ed. 2, p. 173.
MACROPTERA, G. Cotteau. Moll. Foss. de |’Yonne, p. 122.
rrons, T. Wiltshire. Red Chalk of England (Geol. Assoc.), p. 16,
pl. ii, fig. 4.
pDILUVIANA, A. Kunth. Zeitschr. d. deutsch. geol. Gesellsch., vol. xv,
p. 724.
— E. Hichwald. Lethea Rossica, vol. 1, p. 365.
FRONS, Hichwald. Ibid., p. 366.
carInATA, Hichwald. Ibid., p. 367.
RECTANGULARIS, F’. J. Pictet. Mélanges paléont., p. 263, pl. xl, fig. 9.
MACROPTERA, H. Coquand. Mon. Ostrea, Terr. Crét., p. 164,
pl. lxxii, figs. 1—4.
RECTANGULARIS, Coquand. Ibid., p. 187, pl. lxxii, figs. 5—12.
pEcTINATA, Coquand. Ibid., p. 76, pl. xxix, figs. 1—7 (0. colu-
brina).
SERRATA, Coquand. Ibid., p. 79, pl. xvii, fig. 3; pl. xxx, figs. 1—5.
carinata, Coquand. Ibid., p. 129, pl. xlix, figs. 3—9.
RicorpEana, Coquand. Ibid., p. 148, pl. liii, figs. 8—12.
Mitreriana, Coquand. Ibid., p. 155, pl. lix, figs. 11—16.
DILUVIANA, Coquand. Ibid., p. 120, pl. xl, figs. 1—4.
RECTANGULARIS, P. de Loriol and V. Gilliéron. Urgon. infér. de
Landeron, p. 25,
pl. i, figs. 20—
22.
caRINATA, Ff’. Rémer. Geol. v. Oberschlesien, p. 333.

1871.

1872.

OSTREA. 345

Osrrea [AuEcTRyonrA] carrnata, FI’. Stoliczka. Paleont. Indica, Cret.
Fauna S. India, vol. iii,
p. 468, pl. xlviii, fig. 5;
pl. xlix, figs. 1—2.
= — PECTINATA, Stoliczka. Ibid., p. 469, pl. xlviii,
figs. 1, 2.
= — pILUVIANA, Stoliczka. Ibid., p. 466, pl. xlvi, figs.
2a ple xiviieahies:
ee
— macropTerRA, F. J. Pictetand G.Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal.
Suisse, ser. 5), p. 300,
pl. elxxxiv, fig. 5.
— ReEcTANGULARIS, Pictet and Campiche. Ibid., p. 275, pl. clxxxiv,

figs. 1—4.
— Muczertana, Pictet and Campiche. Ibid., p. 309, pl. exciv, figs.
7—9.

— pectinata, Pictet and Campiche. Ibid., p. 321.
— carrnata, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto-
graphica, vol. xx, pt. 1), p. 174,
pl. xxxix, figs. 6—11.
— piLuviaNna, Geinitz. Ibid., pt. 1, p. 176, pl. xxxix, figs. 1—5.
— Frons, Geinitz. Ibid., pt. 2, p. 30, pl. viii, fig. 12.
— opibuviana, EL. Hébert and E. Munier-Chalmas. Annal. Sci. géol.,
vol. vi, p. 119.
— rons, A. J. Jukes-Browne. Quart. Journ. Geol. Soe., vol. xxxi,
p- 295.
— (Atecrryonra) pinuviana, D. Brauns. Zeitschr. f. d. gesammt.
Naturwiss., vol. xlvi,
p. 392.
Atrctryonia ZEILLERI, EL. Bayle. Explicat. Carte géol. France, vol. Iv.
Atlas, pt. 1, pl. clxvi, figs. 1—4.
— carrnata, Bayle. Ibid., pl. exlvii, figs. 1—7.
OstreAa cartnata, J. Gosselet. Esquisse géol. du Nord, iii, pl. xvii,
fig. 4.
Aurcrryonia FRONS, H. Schrider. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxxiv, p. 261.
OsTREA DILUVIANA, A. Fritsch. Stud. im Gebiete der béhm. Kreideformat.,
ili, Iserschicht., p. 120, fig. 95.
— FRONS va. MACROPTERA, W. Keeping. Foss., etc., Neoc. Upware
and Brickhill, p. 102.
-s — var. cartnata, Keeping. Ibid., p. 103.
— macroprerA, O. Weerth. Neocomsandst. im Teutoburg.-Walde
(Paleont. Abhandl., vol. ii), p. 55.
— RECTANGULARIS, Weerth. Ibid., p. 54.
— carinata, C. A. White. Foss. Ostreide N. America (4th Ann.
Rep. U. S. Geol. Surv.), p. 293, pl.
xliii, figs. 1—4.

346

1886.

1888.

a)
—
[e,2)
oO
we)

1900.

1904.

1905.

CRETACEOUS LAMELLIBRANCHIA.

ALECTRYONIA MACROPTERA, H. Trautschold. Neocom. Sably (Nouv.

Mém. Soc. Imp. Nat.
Moscou, vol. xv), p.133.

Ostrea (ALECTRYONIA) prLuvIANA, G. Miiller. Jahrb. d. k. preuss. geol.

Landesanst. fiir 1887,
p. 400.
FRONS, A. Fritsch. Stud. im Gebiete der bohm. Kreideformat., iv,
Teplitz. Sehicht., p. 87, fig. 86.
(ALECTRYONIA) FRONS, O. Griepenkerl. Senon. v. Kénigslutter
(Paleont. Abhandl.,
vol. iv), p. 33.

Atecrryonia cf. carmnata, M. Yokoyama. Paleontographica, vol. xxxvi,

p. 198.

Osrrea FRoNS, S. Meunier. Le Naturaliste, p. 175, fig. 1.

carmnata, R. Michael. Zeitschr. d. deutsch. geol. Gesellsch., vol.
xly, p. 238.
sp. ef. prtuviANnA, Michael. Ibid., p. 239.
pinuviana, B. Lundgren. Mollusk. i Mammillatus och mucronata
zonerna, p. 36.
(Anecrryonra) cartnata, LH. Tiessen. Zeitschr. d. deutsch. geol.
Gesellsch., vol. xlvii,
p- 462.
— ef. piLuviaNnA, Tiessen. Ibid., p. 463.
MACROPTERA, G. Maas. Ibid., vol. xlvii, p. 271.
= A. Wollemann. Ibid., vol. xlviii, p. 834.
cartnata, U. Sihle. Geognost. Jahresh. (1896), p. 40.
— R. Leonhard. Paleontographica, vol. xliv, p. 27.
piLuviana, A. Hennig. Revis. Lamellibr. i Nilssons’s ‘ Petrif.
Suecana,’ p. 16, pl. ii, figs. 1, 2, 5.
(AvEcrryontA) pectinata, F’. Notling. U. Cret. (Maestrichtian)
Mari Hills (Paleont.
Indica, ser. xvi, vol. i),
p. 38, pl. ix, figs. 2, 3.
— rrons, A. Rutot. Bull. Soc. Belge Géol. Paléont.
et Hydrol., vol. x, p. 24.
FRONS, A. Fritsch. Stud. im Gebiete der béhm. Kreideformat., vi,
Chlomek. Schicht., p. 68.
pectinaTa, G. Miiller. Mollusk. Untersen. v. Braunschweig u.
Ilsede (Abhandl. d. k. preuss. geol.
Landesanst., n.F., 25), p. 13, pl. i, fig. 6.
MACROPTERA, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.
hollind. Neocoms (ibid., N.F.,
pt. 31), p. 16.

AxecrryoniaA ZeILuERt, H. Dowvillé. Mission Scient. Perse (J. de Morgan),

vol. iii, pt. vi, Paléont., p. 277,
pl. xxxvi, fig. 16.

Ostrea pinuyviana, T.. Wegner. Zeitschr. d. deutsch. geol. Gesellsch., vol.

lvii, p. 182.

OSTREA. B47

1908. Osrrea (ALEcTRYONIA) MAcRoPTERA, P. A. Peron. Compte rendu Assoc.
Frang. Avance. Sci.,
vol. xxxvi (1907),
p- 308.
1910. — — cartnata, EH. Bise. Mon. geol. paléont. Cerro
de Muleros (Bol. Instit.
geol. Mexico, No. 25), p.
104, pl. xvi, figs. 13, 14.
Iw — (Atecrronta) cartnata, A. Fritsch. Stud. im Gebiete der bohm.
Kreideformat., Koryeaner
Schicht., p. 48, fig. 218.
= — opinuviana, Fritsch. Ibid., p. 48, fig. 216.
— AwLeEcrRyonia pinuviana, K. Vogel v. Falckenstein. Zeitschr. d. deutsch.
geol. Gesellsch., vol. Ixii, p. 559.
P — — cfr. FRONS, Vogel v. Falckenstein. Ibid., p. 559.

Non 1847. Ostrea carrnata, J. Miiller. Petref. der Aachen. Kreidef., pt. 1, p. 38,
(= O. Goldfussi, Holzapfel).
— 1850. — = J. de C. Sowerby, in F. Dixon. Geol. Sussex, p. 357 (0.
frons, p. 386, ed. 2),
pl. xxvui, fig. 2.

— 1852. — vrons? R&R. Kner. Denkschr. k. Akad. Wissensch. Wien, Math.-Nat.
CL. vol. iii, p. 319, pl. xvii, fig. 10.
— 1883. —_— — A, Fritsch. Stud. im Gebiete der bohm. Kreideformat.,

iii, Iserschicht., p. 121, fig. 96.

Description.—Shell nearly equivalve ; the valves similar except for the attached
surface of the left valve. The proportion of height to length varies, but usually
the height is much greater than the length, the difference becoming greater with
age. Valves usually more or less tapering towards the postero-ventral extremity,
but occasionally expanding at the end; slightly, moderately, or considerably
curved, occasionally forming a nearly complete volution; sides flattened, so that
in the elongate forms each valve is roof-like in section. The thickness (or depth)
of the valves increases with age, and in old individuals the shell becomes very
thick and possesses a vesicular structure. Umbones small, with a slight or
moderate posterior curvature. A posterior wing or ear is usually present, and is
of small or moderate size when the attached surface is small, but of large size
when the attached surface is large and mainly posterior to the umbo. <A small
anterior wing is often present, and is best developed in specimens which have a
small attached surface. When the attached surface is small or narrow the shell
becomes elongate, but when the attached surface is large and broad the shell
becomes rounded or oval instead of elongate, and then the posterior ear is usually
not distinctly defined.

348 CRETACEOUS LAMELLIBRANCHIA.

Fias. 98-109.—Ostrea diluviana, L98, 99. Claxby Ironstone, Goulsby. Bristol Museum. Left valve and
anterior view. 100-102, Lower Greensand, Atherfield. Museum of Practical Geology, Nos. 25802, 25790,
25795. Right valves and anterior view. 103, Crackers, Atherfield. Same museum, No. 25793. Right
valve. 104, 105, Lower Greensand, Upware. Sedgwick Museum. Interior and exterior of a left
valve. 106-108, Lower Greensand, Faringdon. 106, 107, Bristol Museum. Left valve. 108, Mr.
Treacher’s Collection. Right valve. 109, Ferruginous Sands, Shanklin. Sedgwick Museum. Right
valve. All x &.

OSTREA. 349

Valves with strong, usually angular folds which, in the elongate forms, extend
from the median line to the margin; the folds are usually somewhat curved, but
may be almost straight; the amount of their curvature decreases in passing from
the earlier to the later part of the shell. The margins of the two valves interlock
by means of sharply pointed tooth-like projections formed by the interspaces
between the folds. On the median ridge of the valves the folds are usually
irregular, and may bear on each side of the ridge short spines; near the margins
of the valves long tubular outgrowths occur in some specimens. The number and
size of the folds vary considerably in different individuals; often the later folds
are stronger than the earlier ones, and those on the convex side stronger than
those on the concave side. The part of the right valve near the umbo is smooth
and without folds so long as the corresponding part of the left valve is attached ;
this portion is commonly small, but becomes extensive when the attached surface
of the left valve is large, and then the folds are limited to the relatively small
marginal part of the valves. The triangular ligament-pit may be slightly or con-
siderably curved. The adductor impression is oval, and usually not far from the
hinge-line.

Affinities —The examples of this species found in the Lower Cretaceous have
been named O. rectangularis, Romer, and O. macroptera, Romer. Pictet and
Campiche, de Loriol, and Weerth regard O. macroptera as distinct from O. rect-
angularis, and state that the former differs from the latter principally in the
relatively smaller height of the shell, the larger posterior wing, and the larger
ribs. D’Orbigny, Maas and Wollemann, on the other hand, consider that the two
forms cannot be separated. The last author, after studying a large collection of
specimens, states that the height of the shell depends mainly on the age of the
individual; that the size of the posterior wing varies greatly, being in some cases
quite small, in others very large, and between the two extremes every gradation
may be found. The size of the ribs likewise varies. The study of numerous
English specimens leads me to endorse Wollemann’s view. Pictet and Campiche
figured as O. macroptera a small example from the Lower Greensand of Atherfield,
but larger specimens from the same horizon possess a higher shell like O. rect-
angularis, and cannot be separated from O. macroptera.

The examples found in the Lower Cretaceous deposits have been generally
regarded as distinct from those in the Upper Cretaceous, which in this country
have been usually named 0. frons or O. carinata. The principal distinction is said
to be the larger posterior wing in the Lower Cretaceous form. But the study of
a large series of specimens shows that in both the Upper and the Lower Cretaceous
the size of the wing varies greatly, as well as the height and curvature of the
shell, and the number and coarseness of the ribs. As a rule, however, the posterior
wing is better developed in the Lower than in the Upper Cretaceous examples,

46

350 CRETACEOUS LAMELLIBRANCHIA.

121

Fras. 110-122.—Ostrea diluviana, L. Sedgwick Museum, except 120, 121. 110, 111, Lower Greensand,
Upware. Left and right valves. 112-119, Lower Greensand, Faringdon. Left valves. 112-114,
anterior, interior and exterior of a left valve. 116, 117, interior and exterior of a left valve. 118,
119, interior and exterior of a left valve. 120,121, zone of Pecten asper, Devizes. Museum of Practical
Geology, Nos. 25814, 25812. 120, right valve. 121, left valve. 122, Chalk Marl, Folkestone. Left
valve. All x §.

OSTREA. 35]

but in some of the former it is small,’ while in some of the latter it attains a large
size (fig. 128), and such specimens are indistinguishable from O. macroptera. It
seems, therefore, that no line can be drawn between O. macroptera and the Upper
Cretaceous forms, especially since it is found that the size of the wing is directly
related to that of the attached surface of the left valve which was almost certainly
determined by external conditions. When the attached surface is large and
mainly posterior to the umbo, then the macroptera type with a large wing arises.

The examples of this species (here known as 0. diluviana, L.), found in the
Upper Cretaceous deposits, have received numerous names, of which the principal
are O. pectinata, Lamarck, O. carinata, Lamarck, O. colubrina, Lamarck, O. frons,
Parkinson, O. serrata, Brongniart, O. prionota, Goldfuss, O. Milletiana, d’Orbigny,
O. Ricordeana, VOrbigny, O. Zeilleri (Bayle). Inthe Upper Cretaceous of England
this species is not known to occur above the zone of Holaster subglobusus and has
been usually named O. frons or O. carinata, but on the continent of Europe and in
other parts of the world it is represented in the higher parts of the Chalk.
D’Orbigny and Coquand, believing in the principle that specimens found at different
horizons belong to different species, have regarded as distinct forms the following
amongst others: O. Milletiana from the Gault, O. cariinata from the Cenomanian, 0.
pectinata (O. frons) from the Lower Senonian, 0. serrata from the Upper Senonian.
But later authors have found the greatest difficulty in distinguishing these
* species.” An examination of a large number of specimens, even when collected
from one locality and one horizon only, shows that the shell is: extraordinarily
variable, and that every gradation is found between the different types ; apart from
variation in the number and size of the ribs, the curvature of the shell, ete., there
are differences which are obviously due to the size, shape and position of the
attached surface. Similar modifications occur at all horizons, and it seems
impossible to separate as distinct species the forms found at different levels.
Sometimes at one locality or in one kind of deposit a particular form of the shell
may be more common than others, and may, if only a small number of specimens
are available, give the impression of being a distinct species, but whenever a large
collection is made other varieties are found which make it impossible to regard as
a species the form which at first sight appeared to be distinct. The difficulty of
separating these supposed species is shown by the fact that although d’Orbigny
states that O. frons is characteristic of the Senonian, yet he includes in his synonymy
the specimens figured by Sowerby from the Upper Greensand and Chalk Marl.
Similarly, in quoting foreign examples of a “‘species,’’ authors have sometimes
unconsciously cited them from horizons in which they believed the species did
not occur.

1 See, for example, a specimen from the Lower Greensand of Faringdon (figs. 106, 107), in
which the left valve was attached to a long narrow object, and the posterior wing is not developed.

352 CRETACEOUS LAMELLIBRANCHIA.

Peron (1908) has already recognised that these “ species’? cannot be accepted.
He states that the detailed analysis of the characters attributed to each of the
species and the study of their synonymy shows that the enchainement of these
diverse forms is complete, and that usually the difference of names corresponds
only to difference of stratigraphical horizon.

The form found in the Gault, which was named O. Milletiana by d’Orbigny, is
considered by Pictet and Campiche to be identical with O. carinata of Sowerby
from the Upper Greensand and Chalk Marl, which, as already mentioned, is
included by d’Orbigny in O. frons of the Senonian. Pictet and Campiche quote
O. Milletiana from the Cambridge Greensand, but this is included by Jukes-
Browne in O. frons.

O. diluviana, Linneeus, from the Upper Chalk of Sweden, was figured first by
Nilsson, and more recently other figures of Swedish specimens have been given by
Hennig (1897). D’Orbigny and Coquand recognised that the specimens figured
by Nilsson as O. diluviana could not be separated from O. frons, and the same
view is held by Brauns, Lundgren, and Hennig. The two last-named authors
state that Nilsson’s figures certainly represent Linnzeus’ species, and Brauns also
takes them as types of O. diluviana, but excludes the figures given by d’Orbigny,
Coquand, Goldfuss and Geinitz. D’Orbigny, on the other hand, takes Hisinger’s
figure of a specimen from the Upper Chalk of Sweden as the type of Linnzus’
O. diluviana, and excludes from that species the forms figured by Nilsson, which
he regards as belonging to O. frons. The examples of O. diluviana figured by
d’Orbigny, Coquand and Geinitz come from the Cenomanian. In O. diluviana, as
understood by those authors, the shell is oval or rounded in form instead of being
elongate as in the common forms of O. frons; at first sight it appears to be quite
distinet, and being easily recognisable it has been commonly regarded as a separate
species,’ but Lundgren and Hennig have found in the Swedish Chalk a large
number of intermediate forms which link together O. diluviana as interpreted by
dOrbigny and O. diluviana as figured by Nilsson and Hennig, consequently these
two types cannot be any longer regarded as distinct species. Geinitz, although
keeping the forms distinct, nevertheless recognises in the Cenomanian of Saxony
the existence of intermediate forms, and the same fact is shown by Goldfuss’
figures. An oval or rounded form, closely resembling O. diluviana as understood
by @Orbigny, is found in the Lower Greensand of Faringdon (figs. 115, 118,
119), and is certainly inseparable from the common elongate form which has
been usually named O. macroptera ; similar remarks apply to a rounded form found
occasionally in the Upper Greensand and Chalk Marl of England (figs. 124, 125).

1H. Douvillé places this in the “genus” Lopha (= Alectryonia), and refers the elongate forms
(frons, carinata, etc.) to the “genus” Arctostrea. See ‘Bull. Soc. géol. de France,’ ser. 4, vol. x
(1910), pp. 6386, 637.

OSTREA. 353

vy
7;

/
S 2) ae

pi > ;

Museum of Practical

British Museum, L3326.

Sedgwick Museum. 126, anterior view. 128-130,

127, anterior view of 128. 131-133, Base of Chalk Marl, Haslingfield. Sedgwick
134, Cenomanian Sandstone, Wilmington. Sedgwick Museum. Vertical

Left valve.

right valves.
Museum. Right valves.
section of left valve. All x &.

554 CRETACEOUS LAMELLIBRANCHIA.

So that this type occurs at three horizons: Aptian, Cenomanian, and Senonian,
and its features are obviously due to the large size and rounded form of the
attached surface; the shell was attached for such a long period that when it
eventually grew free it was unable to develop its usual elongate form, and its
ultimate outline was only a little different from that of its attached surface.
The coarseness of the ribs varies in the same way as in the elongate forms. In
some places, as, for instance, in the Cenomanian of Gamighiigel in Saxony, the
shell attains a great thickness, but the elongate forms likewise sometimes become

very thick.

Fias. 135-138.—Ostrea diluviana, L135, zone of Holaster subglobosus, Cherry Hinton. Right valve. 136-135,
Base of Chalk Marl, Haslingfield, Cambs. 136, 137, Right valves. 188, anterior view of 137.
Sedgwick Museum. All x &.

O. santonensis, @Orbigny, and O. carantonensis, d’Orbigny, are similar to
VOrbigny’s O. diluviana, and are included by Geinitz in that species.

Remarks—The shell varies greatly in its curvature, some examples being only
slightly bent, while others form almost a complete volution (fig. 123), and between
these extremes every gradation isfound. The variation in the coarseness of the ribs
seems, in some cases at any rate, to be connected with the nature and depth of
the sea-floor on which the individuals lived; for example, most of the specimens
found in the Chalk Marl have coarse ribs, but those found in the Cenomanian
sandstone of Wilmington in Devon have smaller and more numerous ribs. Occa-
sionally folds or ribs are developed on the posterior ear (fig. 135). The long
regular outgrowths from the margin of the valves (fig. 122) occur in specimens

OSTREA. BD0

from the Chalk Marl, and were no doubt developed for the purpose of fixation in
the soft sediment of the sea floor.

In all cases the right valve starts with a smooth stage, and folds are developed
later. The smooth stage corresponds with the attached surface of the left valve,
since folding does not begin until the margin of that valve grows free from the
rock or body to which the shell is fixed. Occasionally, after folding has gone on
for some time, a second smooth stage appears on the right valve; this is due to
the left valve becoming again attached to a foreign body (fig. 157).

Types.—O. diluviana, L., from the Senonian of Sweden. O. pectinata, Lamarck,
is said to have come from near Dreux (HEure-et-Loire). 0. carinata, Lamarck,
from Carry (Seine-Infériéure). O. frons, Parkinson, from France; the locality
and horizon are unknown, and the specimen cannot now be found. 0. carinata,
Sowerby, from the Upper Greensand of Chute Farm, near Longleat Park, and from
the Chalk Marl of Folkestone, are in the British Museum. 0. serrata, Cuvier and
Brongniart, came from Dreux. O. macroptera, Sowerby, from the Lower Greensand
of Folkestone, is in the British Museum. 0. retusa, Sowerby, from the Lower
Greensand of Atherfield, cannot be traced.

Distribution.—Claxby Ironstone (zone of Belemnites lateralis) of South Willing-
ham. ‘Tealby Limestone (zone of Belemnites brunsvicensis) of North Willingham,
Lincolnshire. Perna-bed of Atherfield. Ferruginous Sands of Atherfield and
Shanklin. Recorded by Topley from the Sandgate Beds and Folkestone Beds of
Folkestone. Lower Greensand of Faringdon, Brickhill, Potton and Upware.

Upper Gault of Folkestone. Cambridge Greensand. Upper Greensand (zone
of Schlenbachia rostrata) of Blackdown, Devizes, Warminster and Ventnor.
Upper Greensand (zone of Pecten asper) of Devizes. Chalk Marl (zone of Schlan-
bachia varians) of Ventnor, Folkestone, Haslingfield, Burwell, etc. Cenomanian
Sandstone of. Wilmington. Cenomanian (Meyer’s Bed 12) of Dunscombe. Zone
of Holaster subglobosus of Cherry Hinton and Burwell.

Osrrea Leymertt, Leymerie [ex Deshayes], 1842. Text-figs. 139, 140.

1842. Osrrea Leymertt, [Deshayes, MS.], A. Leymerie. Mém. Soc. géol. de
France, vol. v, pp. 11, 28, pl. xiii,

fio. 4.
1845. -- oa FE. Forbes. Quart. Journ, Geol. Soe., vol. i, p. 250.
1843. — -—- A, Leymerie. Statist. géol. min. de l’Aube, Atlas, pl. vii,
fig. 2.
1847. — — A. @Orbigny. Pal. France, Terr. Crét., vol. iii, p. 704,
pl. eccelxix, figs. 1—3.
0. -- _ @ Orbigny. Prodr. de Pal., vol. ii, p. 108.

54, — Leymeriet, J. Morris. Cat. Brit. Foss,, ed. 2, p. 173.

CRETACEOUS LAMELLIBRANCHIA.

1855. Osrrea Leymert, G. Cotteau. Moll. Foss. de ’Yonne, p. 122.

1860. — — A. Gaudry. Bull. Soe. géol. de France, ser. 2, vol. xvii,
p. 30.
? 1861. — — P. de Loriol. Anim. Invert. Foss. Mt. Saléve, p. 112.

Fic. 139.—Ostrea Leymerii, Leym. Mammillatus-bed, Okeford Fitzpaine. British Museum, No. L11597.
Right valve. x j.

1869. — — H, Coquand. Mon. Ostrea, Terr. Crét., p. 179, pl. Ixx,.
figs. 14—17 ; pl. Ixxi, figs. 6, 7.
— lLeymerietr, P. de Loriol and V. Gillieron. Urgon. Infér. du Lan-
deron, p. 27.
1871. — lLeymeru, F. J. Pictet and G.Campiche. Terr. Crét. Ste. Croix (Matér.
Pal. Suisse, ser. 5), p. 296, pl. ce, figs. 1, 2.

OSTREA. 357

1878. Osrreum Leymeriet, E. Bayle. Explicat. Carte géol. de France, vol. iv,
Atlas, pt. 1, pl. exxx, figs. 1, 2.
1897. Osrrea Leymertet, R. B. Newton. Proc. Dorset Nat. Hist. and Antiq.
Field Club, vol. xviii, p. 73, pl. i,
fig. 3.

Deseription.—Shell large, very thick in old specimens, higher than long;
usually slightly or only moderately inequilateral; outline ovate, oval, subtrigonal
or subquadrate. Left valve slightly or moderately convex; right valve often
flattened. Umbonal part sometimes narrow, sometimes broad. Umbo straight or

Fic. 140.—Ostrea Leymerii, Leym. Manmillatus-bed, Okeford Fitzpaine. British Museum, No. L. 11591.
Interior of part of right valve. x 3.

slightly curved ; area large, high. Surface of valves sometimes smooth, except
for growth-lamella, sometimes with radial folds. Attached surface of vari-
able size.

Affinities —This species seems to be related to O. Germaini, Coquand. It also,
as de Loriol pointed out, shows some resemblance to some forms of Mxogyra
sinuata in which the umbo is only slightly curved; but whether it has any-real
relationship to that species cannot at present be determined. See also O. cuna-
bula (below).

Type.—From the Barremian of Aube.

358 CRETACEOUS LAMELLIBRANCHIA.

Distribution —Hythe Beds of Aylesford, Kent. Mammillatus-bed of Okeford
Fitzpaine, Dorset. Recorded by Fitton from the Perna-bed and Ferruginous
Sands of Atherfield. Recorded by Topley from the Atherfield Beds of Peasmarsh
and Sevenoaks.

Ostrea cunaBuna, Seeley, 1861. Text-figs, 141, 142.
1861. Osrrea cunasuna, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. vii, p-
117, pl. v, fig. 1.
— == LAGENA, Seeley. Ibid., p. 117, pl. v, fig. 2.

Description—Shell higher than long, either nearly equilateral or slightly or

Fie, 141.—Ostrea cunabula, Seel. Cambridge Greensand (base of Chalk Marl). Sedgwick Museum.
Cambridge. The type of O. lagena, Seel. Interior and exterior of left valve. x §

o

moderately inequilateral; when nearly equilateral the outline is often ovate
or oval.

Left valve with the attached surface either small and near the umbo only, or
large—sometimes extending to the greater part of the valve; in the former case
the valve is very convex, in the latter slightly convex or flattened. Umbonal part
usually narrow and pointed. Area large, usually higher than long ; sometimes in
the plane of the valves and nearly symmetrical; in other cases curving inwards,
outwards or backwards. Surface usually with numerous, rounded, radiating ribs
crossed by growth-ridges. Adductor impression deep, near the posterior margin,
oval or more or less quadrate. Right valve nearly flat, with growth-lines only.

Affinities.—O. cunabula is closely allied to and may be only a variety of

OSTREA. 359

Fic. 142.—Ostrea cunabula, Seel. Cambridge Greensand (base of Chalk Marl). a, s, British Museum,
No. 67740. c-1, Sedgwick Museum. A, B, left valve. c, left; p. right valve; £, anterior view of c, D.
F, right valve with other oysters on the surface. «a, left valve. u, 1, exterior and interior of a left valve.
All x £

o

360 CRETACEOUS LAMELLIBRANCHIA.

O. Leymerii, from which it appears to differ in its somewhat smaller ribs. The
forms with a small surface of attachment resemble O. baissunensis, Bohm,! but have
coarser and less regular ribs. 0. lagena, Seeley (fig. 141), is a form of O. cunabula
with a very large attached surface, and consequently a less convex left valve.

T'ypes.—From the Cambridge Greensand (indigenous). The type of 0. layena
is in the Sedgwick Museum, Cambridge ; the type of 0. cunabula cannot be found,
but other specimens named by Seeley are in the Sedgwick Museum.

Distribution.—Cambridge Greensand (base of Chalk Marl), Cambridge. Chalk
Mar! of Burwell.

Ostrea Watkert, Keeping, 1883. Plate LV, figs. 1—3.
3 Puig, oS

1883. Osrrea WaLkKext, W. Keeping. Foss., etc., Neoc. Upware and Brickhill,
p. 103, pl. iv, fig. 4.

Remarks.—This form is similar to O. Germaini and O. Leymerti; the chiet
difference mentioned by Keeping—the inequality of the valves—is not constant,
and is determined by the size of the attached surface. Harbort regards 0. Walkeri
as a synonym of O. Germaini, Coquand,* but the material available is hardly
sufficient for definite determination. Some of the specimens with a large attached
surface resemble O. Osmana, Wollemann.®*

Type.—In the Sedgwick Museum, Cambridge.

Distribution.—Lower Greensand of Upware.

.

OstrEA vesicuLaRris, Lamarck, 1806. Plate LV, figs. 4—9. Text-figures. 143—182.

1779. _- B. Faujas-St.-Fond. Hist. nat. Mte. St. Pierre de Maestricht,
pl. xxii, fig. 4; pl. xxv, figs. 2, 5.
1806. Osrrea vesicuLaRis, Lamarck. Ann. Mus. Hist. nat., vol. viii, p. 160, and
vol. xiv (1809), p. 375, pl. xxii, fig. 3.
— — veLromEA, Lamarck. Ibid., p. 160; vol. xiv (1809), p. 374, pl.
xxi, fig. 3 (non deltoidea, Sowerby).

1816. — , W. Smith. Strata identif. Organised Fossils, p. 7, pl. iui, figs. 5—7.
1819. — vesicuLaris, Lamarck. Animaux sans Vert., vol. vi, p. 219.
1820. — convexa, 7. Say. Amer. Journ. Sci., vol. ii, p. 42.

1 «Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. li (1899), p. 466, pl. xxix, figs. 1—3.

2 Coquand, ‘Mon. Ostrea, Terr. Crét.’ (1869), p. 191, pl. lxvi, figs. l14—16. Pictet and Campiche,
‘Terr. Crét. Ste. Croix’ (‘Matér. Pal. Suisse,’ ser. 5, 1871), p. 295, pl. elxxxix, figs. 1—6. Wolle-
manu, ‘ Bivaly. u. Gastrop. deutsch. u. hollindisch. Neocoms’ (1900), p. 18, pl. i, fig. 4. Harbort,
‘Fauna Schaumburg-Lippe’schen Kreidemulde ’ (1905), p. 28.

3 Op. cit. (1900), p. 19, pl. i, fig. 5, pl. ii, fig. 1.

OSTREA. 361

Osrrea vestcuLaris, A. Brongniart. In Cuvier, Ossemens Foss., vol. ii,
p- 598, pl. in, fig. 5.
GrypH®a axtoposa, J. de C. Sowerby. Min. Conch., vol. iv, p. 127,
pl. ecexcii.
Ostrea vestcuLaris, S. Nilsson. Petrific. Suecana, p. 29, pl. vii, figs. 3—5,
pl. viii, figs. 5, 6.
— HIpPopopiIuM, Nilsson. Ibid., p. 30, pl. vii, fig. 1.
— cxavata, Nilsson. Ibid., p. 30, pl. vil, fig. 2.
GrypHma convexa, S. G. Morton. Journ. Acad. Nat. Sci. Philad., vol. vi,
Datos pls diese lees
-— mMuTABILIS, Morton. Ibid., p. 81, pl. iv, fig. 3.
-— EXxPANSA, J. de C. Sowerby. In Sedgwick and Murchison, Trans.
Geol. Soc., ser. 2, vol. i, pp. 549,
418, pl. xxxviii, fig. 5.
OstREA vesicuLaris, G. P. Deshayes. Hist. nat. Vers et Mollusques
(Eneyel. méthod.), vol. ii, p. 291.
-— — A. Goldfuss. Petref. Germ., vol. ii, p. 23, pl. Ixxxi,
fig. 2.
— HIPPOPODIUM, Goldfuss. Ibid., p. 23, pl. lxxxi, fig. 1.
GrypHma convexa, S. G. Mortun. Synopsis Org. Remains Cret. U. States,
p- 593, pl. iv, figs. 1, 2.
— MuTABILIS, Morton. Ibid., p. 53, pl. iv, fig. 3.
Pycnoponte rapiata, G. Fischer de Wuldheim. Bull. Soc. Imp. Nat.
Moscou, vol. viii, p. 119, pl. i.
OsTREA VEsIcuLaRIS, W. Hisinger. Lethza Suecica, p. 46, pl. xii, fig. 2.
— uHrppopopium, Hisinger. Ibid., p. 47, pl. xiii, fig. 4.
— cuavata, Hisinger. Ibid., p. 47, pl. xiii, fig. 3.
GRYPHHA simiuis, G. G. Pusch. Polens Paliont., p. 34, pl. iv, fig. 12.
OstREA vEsicuLaRIs, A. d’Archiac. Mém.Soe. géol.de France, vol. ii, p. 183.
— proposcIpEA, @’Archiac. Ibid., p. 184, pl. xi, fig. 9.
— vesicuLaris, F. Dujardin. Ibid., vol. ii, p. 229.
GRYPH#A VESICULARIS, H. G. Bronn. Lethea Geogn., vol. ii, p. 264, pl.
xxxil, fig. 1.
— (OsTREA) VEsIcULARIS, I’. v. Hagenow. Neues Jahrb. fiir Min.,
etc., p. 548.
GRYPH#HA VESICULARIS, H. B. Geinitz. Grundr. d. Verstein., p. 483,
pl. xx, figs. 17, 18.
OsrrEa veEstcuLaRis, A. d’Orbigny. In Murchison, de Verneuil and de
Keyserling, Géol. Russie de
l'Europe, vol. ii, p. 491.
— — A. Leymerie. Statist. géol. min. de l’Aube, Atlas,
pl. iv, fig. 1.
— — A. E. Reuss. Die Verstein. der béhm. Kreideformat.,
pt. 2, p. 37, pl. xxix, figs. 21, 22; pl.
xxx, figs. 1—8.
HIPPOPODIUM, Reuss. Ibid., p. 39, pl. xxviii, figs. 1O—15, 17,18
pl. xxix, figs. 1—18; pl. xxx, figs.
13, 14 (¢ partim).

362 CRETACEOUS LAMELLIBRANCHIA.

1847.

OstREA HIPPopopiuM, A. d’Orbigny. Pal. Frange. Terr. Crét., vol. iii, p.
731, pl. eccelxxxi, figs. 4—6; pl.
cceelxxxil.

-— VESICULARIS, @’Orbigny. Ibid., p. 742, pl. eccelxxxvii.

-— -- J. Miller, Petref. der Aachen. Kreidef., pt. 1, p. 37.

-- HIPPOPODIUM, Miiller. Ibid., p. 39.

GrypH©®A GLoBosa, J. Brown. Illustr. Foss. Conch. Great Britain and

Treland, p. 148, pl. Ixi, fig. 2.
— == var. DEPRESSA, J. de C. Sowerby, in F. Dizon. Geol.
Sussex, p. 357, pl. xxvii, fig. 3.
Osrrea sp., Sowerby. Ibid., p. 357, pl. xxviii, figs. 22, 23.
GryYPHmA veEsIcULARIS, R. Kner. Kreidemerg. v. Lemberg (Haidinger’s
Naturwiss. Abhandl., vol. iii, pt. 2),
p- 30.
OsrREA vesrcuLARIS, A. Alth. Geogn.-paleont. Beschreib. v. Lemberg
(ibid., vol. ii, pt. 2), p. 252.

— HIPPOPODIUM, Alth. Ibid., p. 253, pl. xiii, fig. 3.

— vestcutaris, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 256.

— Lesurvrt, d’Orbigny. Ibid., p. 171.

— Nitssont, J. Miiller. Petrefact. Aachen. Kreideformat., pt. 2,

p- 70.
VESICULARIS, A. Leymerie. Mém. Soc. géol. de France, ser. 2, vol. iv,
p- 202, pl. x, figs. 2, 3.
GryPHmA vestcuLaRis, H. G. Bronn and F. Rimer. Lethea Geogn.,
ed. 3, vol. 1, pt. 5, p. 264, pl. xxxii, fig. 1.
= -- R. Kner. Denkschr. Akad. Wissensch. Wien,
Math.-nat. Cl., vol. iii, p. 319.
OsTREA VESICULARIS var. AUCELLA, F. Romer. Kreidebild. v. Texas, p. 74,
pl. ix, fig. 4.

— uHrppopopium, J. Morris. Cat. Brit. Foss., ed. 2, p. 173.

— vesicunaris, Morris. Ibid., p. 174.

GrypHma vesicunaris, K. EL. Schafhdiutl. Siid-Bayerns Lethewa Geogn.,

p. 148, pl. xli, figs. 5, 6.

OstREA vesicuLaris, A.v. Strombeck. Zeitschr. d. deutsch. geol. Gesellsch.,

vol. xv, pp. 127, 157.
= vesicutosa, S. P. Woodward. Geol. Mag., vol. i, p. 112, pl. vy,
fig. 6.
— uncineLLA, A. Leymerie. Bull. Soc. géol. de France, ser. 2,vol. xxii,
p. 367.

— (GrypHma) vesicunaris, K. A. Zittel. Bivalv. d. Gosaugeb.
(Denkschr. Akad. Wissensch. Wien, Math.-nat. Cl.,
vol. xxv, pt. ii), p. 123 [47], pl. xix, fig. 6 (? partim).

— vesicunaris, B. Lundgren. Paleont. Iakttag. Fiixekalk. Limhamn,

p. 238.
— — O. Fraas. Aus dem Orient, i, p. 88.
— uHrppopopium, EH. Eichwald. Lethea Rossica, vol. ii, p. 387,
pl. xix, fig. 5.
GrypH#A vesicuLaris, Vichwald. Ibid., p. 394.

1869.

1872.

OSTREA. 363

Osrrea vesicuLaris, H. Coquand. Mon. Ostrea, Terr. Crét., p. 35, pl. xiii,
figs. 2—10.
— _ uippopoprum, Coquand. Tbid., p. 100, pl. xviii, figs. 1, 4, 5; pl. xix;
pl. xx, figs. 1—8.
-— Lesveurt, Coquand. Ibid., p. 146, pl. xli, figs. 1—4.
— PRoBoscipEA, Coquand. Ibid., p. 72, pl. xv, fig. 10; pl. xvi, figs.
1—12;; pl. xviii, figs. I—5.
— vesicunartis, HE. Favre. Moll. Foss. de Lemberg, p. 160.
— Hrppopopium, Favre. Ibid., p. 161.
— — F. Rimer. Geol. v. Oberschles., p. 315, pl. xxxvii,
fig. 7.
— vestcunaris, H. Credner. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxii, p. 225.
_ —- C. Schliiter. Neues Jahrb. fiir Min., ete., p. 952.
GrypeHma vestcunartis, I’. Stoliczka. Paleont. Indica, Cret. Fauna 8. India,
vol. ili, p. 465, pl. xlii, figs. 2—4; pl.
xliti, fig. 1; pl. xlv, figs. 7—12.
OstrEA HIppopopium, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal-
eontographica, vol. xx, pt. 1), p. 177, pl. xxxix,
figs. 12—27; - pl. xl, figs. 1—3; pt. 2, pl. vii,
figs. 5—7.
— vestcunarts, J. I. Lahusen. Foss. White Chalk of Simbirsk (Imp.
Russ. Min. Corps Instit.), pt. 2,
p- 249.
— — var. supatca, L. Lartet. Annal. Sci. geéol., vol. iu,
p. 69, pl. xi, figs. 8—10.
— — A. J. Jukes-Browne. Quart. Journ. Geol. Soc., vol.
xxxi, p. 295 ( partim).
GrypHea vestcuLaris (?), F. B. Meek. Invert. Cret. and Tert. Foss. U.
Missouri, p. 20, pl. xi, fig. 2; pl. xvi, fig. 8.
OsrreA HIppopopium, D. Brauns. Zeitschr. f. d. gesammt. Naturwiss.,
vol. xlvi, p. 394.
— — A. Fritsch. Stud. im Geb. béhmisch. Kreideformat.,
: ii, Weissenberg. u. Malnitz. Schicht.,
p. 140, fig. 137.
-- vestcuLaris, 0. Fraas. Aus dem Orient, 11, p. 86.
_- -- J. de C. Sowerby, in F. Dizon. Geol. Sussex, ed. 2,
p. 386, pl. xxvil, fig. 3,
Pycnoponra vestcutaris, EH. Bayle. Explic. Carte géol. France, vol. iv,
Atlas, pt. 1, pl. exxxv, figs. 1—7.
= proposciwkA, Bayle. Ibid., pl. exxxvi, figs. 1, 2.
Osrrea Hipporopium, (. Barrois. Ann. Soc. géol. Nord, vol. v, p. 407.
a — G. Behrens. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxx, p. 260.
Avicua Finata, R. Etheridge, in Penning and Jukes-Browne. Geol. Cam-
bridge, p. 144, pl. ii, fig. 3.
Osrrea cf. HIPPOPODIUM, RP. Windmiller. Jahrb. d.k. preuss. geol. Landes-
anst., fiir 1881, p. 29.

364

1884.

1890.

1890-91.

? 1891.

1894.

CRETACEOUS LAMELLIBRANCHIA.

Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxxiv, p. 259.
Ibid., p. 259.
Stud. im Geb. béhmisch. Kreideformat.,
iii, Iserschicht., p. 122, fig. 98.
4th Ann. Rep. U.S. Geol. Survey,
p. 303, pl. xlviii, figs. 1—5.
R. P. Whitfield. Brach. and Lamellibr. Raritan Clays
(Mon. U. 8. Geol. Surv., vol. ix), p. 36, pl. iii,
figs. 15, 16; pl. iv, figs. 1—3; pl. v.
G. Miller. Jahrb. d. k. preuss. geol. Landesanst.,
fiir 1887, p. 401.
Hist. Terr. Craie 8.E. Bassin Anglo-
Parisien, p. 179.
(GrypHma) vesicuLaris, 0. Griepenkerl. Paleont. Abhandl., vol.
iv, p. 37.
Die Mollusk. Aachen Kreide
(Palxontographica, vol. xxxv),

GryPH®A VEsIcULARIs, H. Schrider.

OstREA HIPPOPODIUM, Schrider.
A. Fritsch.

GrypH®a vesicuLaris, C. A. White.

OsTREA VESICULARIS, A. Peron.

Hippopopium, LH. Holzapfel.

p. 252, pl. xxix, figs. 3—7.
Grypuma vesicutarts, Holzapfel. Tbid., p. 253, pl. xxix, figs. 1, 2.
M. Blanckenhorn. Beitr. Geol. Syriens, p. 75.
Brachiopodes etc., Terr. Crét. Hauts-
Plateaux de la Tunisie, p. 152.
Tbid., p. 175.

Palzontographica, vol. xxxvili, p. 91,

OsrREA HIPPOPODIUM, A. Peron.

— VESICULARIS, Peron.
GryYPH®A VESICULARIS, J. Bohn.
pl. iv, fig. 3.

OstrEA HIPPoPODIUM, Béhm. Ibid., p. 92, pl. iv, fig. 12.

E. Stolley. Mittheil. a. d. Min. Institut. Univ. Kiel,
vol. i, p. 235.

Tbid., p. 236.

Verhandl. nat. Vereins preuss. Rheiul.,

GRYPHHA VESICULARIS, Stolley.
OsvREA VESICULARIS, F’. Vogel.
vol. xlix, p. 51.
A. Hennig. Geol. Foren. i Stockholm Forhandl.,
vol. xvi, p. 515.

urpropopiuM, Hennig. Ibid., p. 514.

vestcunaris, B. Lundgren. Mollusk.i Mammillatus och Mucronata
zonerna, p. 39.

Tbid., p. 36.

Holliindisch. Kreide, p. 7.

HIppopopiuM, Lundgren.

(GrypHma) vestcuaris, I’. Vogel.

nippopopium, Vogel. Ibid., p. 7.

—— (Gnypyma) uippopovium, E. Tiessen. Zeitschr. d. deutsch. geol.

Gesellsch., vol. xlvii, p. 464.
Trans. Roy. Soc. Canada, ser. 2,

vol. i, p. 120.

Revis. Lamellibr. Nilsson’s ‘“ Petrif.

Suecana,”’ p. 6, pl. i, figs. 1—6, 8, 9.

GrypHma vestcuLartis, J. F. Whiteaves.
Osrrea uipporopium, A. Hennig.

vesrcuLaris, Hennig. Ibid., p. 18.

utppopopium, R. Leonard. Paleontographica, vol. xliv, p. 51.

1900.

1901.

1901.

OSTREA. 365

GRYPHHA vesicuLaris, F. Nitling. U. Cret. (Mestrichtian) Mari Hills
(Paleont. Indiea, ser. xvi, vol. i),
p- 39, pl. x, figs. 1, 2.
Osrrea vestcuLaris, A. Rutot. Bull. Soc. Belge Géol. Pal. et Hydrol., vol.
x, p. 26.
— uipporovium, Rutot. Ibid., p. 26.
= = G. Miller. Molluskenfauna Untersen. v. Braun-
schweig u. Isede, p. 14, pl. ii, figs.
10—15; pl. iv, figs. 1, 2.
— — G. de Alessandii. Paleontogr. Italica, vol. iv,
p. 200.
OstREA HIPPOPODIUM, Alessandri. Ibid., p. 199.
OstREA (GRYPH®A) vestcuLaRis, C. Mayer-Eymar. Ecloge Geol. Helvet.,
vol. vi, p. 121.
GRYPH#HA VestcuLArRis, A. Wollemann. Jahrb. d. k. preuss. geol. Landes-
anst., vol. xxi, p. 14.
GRYPHHA VESICULARIS, H. Imkeller. Paleontographica, vol. xlviii, p. 40,

pl. ui, figs. 2—4.; pl. iu, figs. 7—9.

1901-02. Osrrea (Pycnoponra) vestcuLaris, P. Choffat. Faun. Crct. Portugal,

1902.

1903.

?

1906.

vol. i, ser. 3, p. 103,
pl. ii, fig. 18.
GryYPHHA vestcuLaRis, A. Wollemann. Limeburg. Kreide (Abhandl. d. k.
preuss. geol. Landesanst., N.¥.,
37), p. 52.
OstREA HIPPOPODIUM, J. P. J. Ravn. Mollusk. i Danmarks Kridtafl. I.
Lamellibr., p. 114.
GryPHmA vesicuLaRis, Ravn. Ibid., p. 116.
-— -— J. Wanner. Paleontographica, vol. xxx (2), p.
119, pl. xvii, figs. 10—12.
— — E. Dacqué. Ibid., p. 188, pl. xxii, figs. 1, 2.
— — J. A. Taff. Chalk of S. W. Arkansas (22nd Ann.
Rep. U.S. Geol. Surv., pt. iii), pls.
1—lii.
OstrEA vesicuLaRis, FR. Fortau. Bull. Inst. Egyptien, ser. 4, vol. iv, p. 308.
GRYPHEZA vestcuLaRis, J. F. Whiteaves. Mesoz. Foss. (Geol. Surv.
Canada), vol. i, p. 401.
Pycnoponta vestcuLaris, H. Dowvillé. Mission Scient. en Perse par J. de
Morgan, vol. iii, pt. 4, Paléont.,
p. 278, pl. xxxvi, fig. 28.
GRYPHHA VEsicuLaRIs, T. Wegner. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. lvii, p. 184.
Ostrea vesicuLaris, A. D. Arkhangelsky. Ann. géol. min. Russie, vol. vii,
; pp. 190, 205, pl. iv, figs.
1, 2.
GRYPH#A VEsIcULARIS, H. Bise. Fauna Senon. Cirdenas (Bol. Instit.
geol. México, No. 24), p. 49, pl. iv,
figs. 1—3; pl. vii, fig. 2; pl. ix, fig. 4;
pl. xii, fig. 6.

48

366 CRETACEOUS LAMELLIBRANCHIA.

1906. OstreaA (GrypH#A) veEsiIcuLaRiIs, M. Boule and A. Thevenin. Amnal.
Paléont., vol. i, p. 49 [7], pl. ii, fig. 3.

? — GrypHma vesicuLaris, J. Pethi. Paleontographica, vol. lii, p. 188, pl.
xii, figs. 2, 3.
1907. — conyexa, S. Weller. Cret. Pal. New Jersey, p. 451, pl. xlv.
1910. — vEsIcuLARIS, IF’. Frech. Neues Jahrb. fiir Min., ete., i, p. 6,
pl. ii, fig. 1.
? — Osrrea vesicuLaris, H. Briiggen. Ibid., Beil.-Band xxx, p. 744.
1911. = HIpPoPODIUM, A. Fritsch. Stud. im Geb. béhmisch. Kreideformat.,
Korycaner Schicht., p. 48, fig. 217.
» — GrypHea vesicuLaris, M. HE. Vadisz. Mitteil. Jahrb. ungarisch. geol.

Reichsanst., vol. xix, p. 110,
pl. iii, fig. 3.
— Osrrea HIpporpopium, W. Rogala. Bull. Internat. Acad. Sci. Cracovie,
p. 167.
— —- — K. Vogel von Falckenstein. Zeitschr. d. deutsch.
geol. Gesellsch., vol.
Ixii, p. 558.
— GrYPH@A VESICULARIS, v. Falckenstein. Ibid., p. 560.

Non 1859. Osrrea vestcunaris, 7. Wiltshire. Red Chalk of England (Geol. Assoc.),
p. 16, pl. ii, fig. 5.

Description—The left valve, when attached by only a very small part of the
umbo, has a grypheate form, being usually very convex, and with the umbo
prominent and incurved; the outline of the valve is rounded, but the posterior
part is more or less produced ; the postero-dorsal part is often convex and some-
times distinctly limited from the remainder of the valve; this convex part when
strongly developed may be produced backwards in a wing-like form. In large
specimens of the grypheate form this valve becomes very thick.

When the left valve is attached to a larger surface of more or less rounded
outline it is still grypheate in form, but with the umbonal region truncated owing
to the attached surface being flat or concave. When the attached surface is still
larger, relatively to the entire shell, the free marginal part possesses the same
character as the corresponding part of the grypheate form, and this free part
grows upwards from the attached surface. When nearly all the valve is attached
then only a narrow rim grows upwards at the margin; lastly, in some cases the
entire valve is attached so that the whole of it is flat or concave; in the interior
of such forms a few distinct concentric ridges are often found at intervals, and
from the outermost of these the marginal part of the valve becomes gradually
thinner and usually shows a porous structure.

When the left valve is attached to a cylindrical or other elongate object, the
form of the shell depends on the direction of the long axis of the attached surface.
If the axis is nearly perpendicular to or forms a considerable angle with the plane

OSTREA. 367

Fias. 143-153.—Ostrea vesicularis, Lam. 143-145. Upper Greensand (zone of P. asper), Warminster.
Museum of Practical Geology, Nos. 25948, 25950. 143, left valve. 144, right valve. 145, anterior
view of 144 showing both valves. 146. Zone of Micraster cor-anguinum, Witherington, Dr.
Blackmore’s Collection. Interior of left valve. 147. Zone of Actinocamax quadratus, East
Harnham. Same Collection. Right valve. The left valve is entirely attached to the convex
surface of an echinoid. 148, 149. Zone of Micraster cor-anguinum, Gravesend. British Museum,
No. L. 20991. Exterior and interior of a left valve. 150-153. Zone of Belemnitella mucronata,
Norwich. 150, right valve, British Museum, No. L. 20616. 151, Dorsal view of 150 showing both
valves; the left valve entirely attached to a nearly flat surface. 152, 153. Sedgwick Museum.

Left and right valves. 146, 147, natural size. Other figures x 4.

368 CRETACEOUS LAMELLIBRANCHIA.

of the valves the left valve becomes convex; if the axis is more or less parallel to
the plane of the valves and to the hinge-line the left valve is less convex; and if
in such cases the attached surface is mainly in front of the umbo then the anterior
part of the shell becomes elongated, whereas, when the attached surface is mainly
posterior to the umbo the posterior part of the shell become elongated and the
shell more inequilateral ; if the long axis of the attached surface extends from the
umbo in a postero-ventral direction the shell becomes oblique and very inequi-
lateral. Occasionally the left valve shows two surfaces of attachment, one at the
umbo, the other at some distance from it. Since the direction of growth depends
mainly on the position of the attached surface, it is obvious that the relative length
and height will be determined in the same way.

The surface of the free part of the left valve is smooth except for growth-
lines. The form and direction of the umbo, area and ligament-pit depend on the
mode of attachment. The area is either nearly parallel to the attached surface or
slopes gently from the hinge-line to the umbo, and consequently in the grypheate
forms it eventually becomes more or less nearly perpendicular to the plane of the
valves of the adult shell, but in completely attached forms the area and ligament-
pit remain nearly parallel to the plane of the valves; between these two extremes
every gradation can be traced. The ligament-pit and the umbo may curve
forwards or backwards, or be perpendicular to the hinge-line. Small, irregular,
rounded ridges or crenulations, more or less nearly at right angles to the margin
of the valve, are seen on the inside of the shell on each side of the area, but are
most developed on the posterior side. The adductor impression is rounded or
slightly oval.

The ight valve in the grypheate form with a very small attached surface is
almost entirely concave or sometimes nearly flat. The part of the right valve
which corresponds to the attached part of the left valve is more or less convex,
and reproduces the detailed markings as well as the general form of the attached
surface ; when the latter is flat the corresponding part of the right valve is only
shghtly convex, and its convexity increases with that of the attached surface. As
soon as the left valve grows free from the attached body the corresponding part of
the right valve becomes concave and grows upwards at a considerable angle with
the earler convex part. When the entire left valve is attached the whole of the
right valve is shghtly convex and there is no upward growth of the marginal part.
When the outer layer of the right valve is well preserved fine thread-like radial
ribs are seen; they are widely separated and either straight or slightly irregular.
The inner margin near the area has small ridges like those of the left valve.

Affinities. —Vhe study of a large series of specimens shows clearly that Ostiea
hippopodium, Nilsson, is only a form of O. vesicularvis in which the entire or almost
the entire surface of the left valve is attached, and consequently that valve is

OSTREA. 369

—— OT (i

a >

Fias. 154-167.—Ostrea vesicularis, Lam. Zone of Belemnite/la m ucronata, Norwich. Sedgwick Museum,
Cambridge; except 156, 157, in Dr. Rowe’s collection. 154, 156, 159, 161, 163, 164, 166, left
valves. 155, right valve of 154. 157, right valve of 156. 158, interior of a right valve
similar to 157. 160, right valve of 159. 162, right valve of 161. 165, right valve of 164.
167, dorsal view of 166. 166 and 167, natural size. Other figures x §.

370 CRETACEOUS LAMELLIBRANCHIA.

either nearly flat (fig. 151) or grows upward near the margin only (fig. 145),
and the right valve is either slightly convex throughout (figs. 147, 150) or with
a narrow marginal part growing upwards (fig. 155). Although this type differs
greatly in appearance from the grypheate form (fig. 182), yet every stage between
the two extremes can be seen since there is a complete gradation from forms in
which the entire surface is attached to forms in which only a very small part of
the umbo is fixed. But whatever the form of the shell the part, if any, which
grows free shows similar characters. This view of the relationship of O. hippo-
podium and O. vesicularis has already been maintained by Peron (1890) and by
Miiller (1898).

In the Chalk of this country numerous examples of the left valve of an oyster
attached completely to flat or convex objects are found and have been commonly
referred to O. Normaniana, VOrbigny! (fig. 146). The right valve is nearly always
missing. The marginal part of the left valve thins away rapidly to a sharp edge
and this part usually shows a porous structure, whilst on the inner part of the
valve a few distinct concentric ridges are seen ; some of these specimens are young
individuals and many are probably immature; the concentric ridges probably
indicate the beginning of an upward growth of the margin which was soon dis-
continued and the attached growth resumed. Similar concentric ridges are present
in some undoubted examples of O. vesicularis (figs. 148, 149), and the identity of
this form with O. vesicularis is proved by the occasional preservation in its original
position of the right valve (Plate LV, fig. 4; text-fig. 147) showing the charac-
teristic radial ornamentation of O. vesicularis. A left valve of this form is figured
by Geinitz? as O. hippopodiwm.

Avicula filata, Etheridge, from the Totternhoe Stone (zone of Holaster sub-
globosus) of Burwell, is founded on a right valve of a small specimen of O. vesicu-
laris, and shows clearly the fine radial ribs. It agrees with small specimens
attached throughout or with only the margin free, found in the Upper and Lower
Chalk as well as in the Gault? (Plate LV, figs. 4, 5, 7; text-fig. 147).

QO. clavata, Nilsson, is a form in which the posterior part is more produced than
usual owing to the position of the attached surface.

The hippopodium form of O. vesicularis found in the Cenomanian was named
O. Lesuewrt by V@Orbigny on account of its lower horizon. But Hennig, who has
studied a series of Cenomanian specimens, sees no reason for separating it from
the Senonian examples, and Miiller (1898) likewise includes it in O. vesicularis.

2 «Pal. Frang. Terr. Crét.,’ vol. iii (1847), p. 746, pl. eccelxxxviii, figs. 1—3.

* «Paleontographica,’ vol. xx, pt. 2, pl. viii, fig. 6.

8 Anomia subradiata, Reuss, is probably a small example of O. vesicularis similar to Avicula
filata of Etheridge. Reuss, ‘Die Verstein. der bohm. Kreideformat.,’ pt. 2 (1846), p. 45, pl. xxxi,
fie. 19.

5

OSTREA. 371

es

180

Fias. 168-181.— Ostrea vesicularis, Lam. Zone of Belemnitella mucronata, Norwich. 168, 169, left and
right valves. Norwich Museum, No, 2133. 170,171, left andright valves. Dr. Rowe’s Collection.
172, 173, left and right valves. Sedgwick Museum. 174, 175, left and right valves. Norwich
Museum. 176-179, left valves. Sedgwick Museum. 178, posterior view of 177. 180, 181, left
valve. Dr. Rowe’s Collection. 181, anterior view of 180. All x §.

372 CRETACEOUS LAMELLIBRANCHIA.

0. proboscidea, d’Archiae, is included by Zittel and by G. Miiller in O. vesicularis,
and the latter points out its probable close connection with O. biauriculata,
Lamarck. The type of O. proboscilea from the Santonian of Saintes, Dordogne, is
not quite satisfactory, but most of the specimens figured by Coquand seem to be
inseparable from O. vesicularis.

The grypheate forms of O. vesicularis have been usually placed in the “ genus”
Gryphea, and the hippopodium forms in Ostrea; in the case of this species, at any
rate, “ Gryphea” cannpt be accepted as a genus.’

In the Lower Chalk (Plate LV, figs. 8, 9) a small grypheate form® varying
only to a small extent in dimensions is common and is not usually associated with
larger forms; the uniformity in size and character of this form at first give the
impression that it may be a distinct variety, but comparison with the small forms
of O. vesicularis from the Upper Chalk (figs. 166, 167) shows that they cannot be
separated; their small size was probably due to local conditions. Further, it may
be noted that in earlier beds (the Upper Greensand) large forms of both the
erypheate and hippopodium types occur (figs. 143—145), and are indistinguishable
from those found in the Upper Chalk. Some rather small grypheate forms are also
found in the Gault and Cambridge Greensand, and also forms with all or the larger
part of the left valve attached, but they are not common in the Gault.

A few specimens of a small oyster have been found in the Lower Greensand of
Atherfield and Shanklin, and show the fine radial ribs on the right valve®; some
of these, and probably all, are examples of O. vesiculavis, but the left valves are
not, in all cases, well preserved.*

Remarks.—O. vesicularis attains its greatest development in the zones of
Belemnitella mucronata and Ostrea lunata in this country, where the grypheate
forms are abundant and reach a large size. The form with the posterior wmg-
like projection (figs. 174-179) occurs mainly in the zone of B. mucronata. O. vest-
cularis has been observed attached to sponges, corals, echinoids, oysters, Inoceramus,
Spondylus, gasteropods, Ammonites, and Belemnitella. The long range in time
and the wide geographical distribution of this species have already been noted by
Hennig and other authors.

Types.—O. vesicularis, Lamarck, and O. deltoidea, Lamarck, from the Upper
Chalk of Meudon. Gryphea globosa, Sowerby, from the zone of DBelemmnitella

1 This conclusion is in agreement with Peron’s views on the “genera” of the Ostreide; see
‘Descript. Brach., ete., Terr. Crét. Tunisie’ (1890—91), pp. 107—109.

2 A similar but rather larger form occurs in the Melbourn Rock and plenus-marls.

3 Examples of tins are figured in vol. i, pl. v, figs. 4, 5

4 Ostrea virgata, Sowerby, possesses numerous fine radial ribs. The type is the only specimen
known ; it was found in the Lower Chalk (probably zone of Holaster subglobosus) of Sussex. The
affinities of this form cannot be determined. Dixon, ‘ Geol. Sussex’ (1850), p. 357, pl. xxvii, fig. 1.

OSTREA. 073

mucronata of Norwich, is in the British Museum. — O. hippopodinm, Nilsson, from
the Upper Chalk of Kopinge, is in the Lund Museum. ‘The specimens of O. hippo-
podium figured by Goldfuss from the Cenomanian of Essen, are in the Munich
Museum. The examples of. O. vesicularis figured by William Smith came from
Norwich and are in the British Museum. The original of Giryphea globosa var.
depressa, Sowerby (in Dixon), cannot be found; the specimens of Ostiea figured by
the same author (Dixon, pl. xxviii, figs. 22, 25), from the zone of Holaster subhglobosus
near Warminster, are in the British Museum. The specimen figured by 8. P.
Woodward as O. vesiculosa from the Upper Chalk of Sussex, is also in that Museum.
Aviculu filata, Etheridge, from the Totternhoe Stone of Burwell, is in the Sedgewick

Museum.

Fic. 182.—Ostrea vesicularis, Lam. Zone of Ostrea lunata, Trimingham. Dr. Rowe’s Collection. Left
valve. x &

Distribution.—Lower Greensand (Ferruginous Sands) of Shanklin. Gault of
Folkestone. Cambridge Greensand. Upper Greensand (zone of Schlanbachia
rostrata) of the Isle of Wight. Upper Greensand (zone of Pecten asper) of War-
minster.

Chalk Marl (zone of Schlanbachia varians) of Folkestone, Offham, and Burwell.
Cenomanian (Meyer’s bed 11) of Beer Head. Cenomanian Sandstone of
Wilmington.

Zone of Holaster subglobosus of Chileomb (Hants), Glynde (Lewes), Burham,
Arlesey, Ickleford (near Hitchin), Cherry Hinton, Burwell, and Isleham.

Zone of Rhynchonella Cuvieri of the South Devon coast and Dover. Melbourn

Rock, Melbourn.
49

374. CRETACEOUS LAMELLIBRANCHIA.

Zone of Terebratulina lata of the South Devon coast, Dover, Cuxton, Charing,
and Beachy Head.

Zone of Holaster planus of Mupe Bay, Borstal, West Wratting, Cheveley, and
Swaffham (Norfolk).

Zone of Micraster cor-testudinarium of Borstal Manor, Chatham, and Stevenage.

Zone of Micraster cor-anguinum of Witherington, Quidhampton, Camp Hill
(near Salisbury), Northfleet, Gravesend, and the Thanet coast.

Zone of Marsupites testudinarius of the Thanet coast. Uintacrinus band of
Devizes Road (Salisbury).

Zone of Actinocamax quadratus of Whaddon, East and West Harnham, Fareham,
Shawford, and Bishops Waltham.

Zone of Belemnitella mucronata of the Dorset coast and Norwich.

Zone of Ostrea lunata of Trimingham.

Ostrea vesicuLosa (Sowerby), 1822. Plate LV, figs. 10—14; Plate LVI, fig. 1.

1822. GrypHma vestcuLosa, J. Sowerby. Min. Conch., vol. iv, p. 93, pl. ecelxix.
? 1847. Osrrea vascutum, A. d’Archiac. Mém. Soc. géol. de France, ser. 2, vol. ii,
p. 312, pl. xvi, figs. 5, 6.
1849. GrypHma vestcunosa, 7. Brown. TIllustr. Foss. Conch. Gt. Brit. and
Ireland, p. 149, pl. 1xi, figs. 8, 9.
1850. Osrrea vestcuLosa, EH. Guéranger. Bull. Soc. géol. de France, ser. 2,
vol. vii, p. 802.
1854. GrypHma vesicutosa, J. Morris. Cat. Brit. Foss., ed. 2, p. 168.
? 1868. OsrrEea cotumsa, A. Briart and F. L. Cornet. Meule de Bracquegnies
(Mém. cour. et Mém. des Sav. ctrangers, vol. xxxiv),
p- 46, pl. iv, figs. 13—15.

1869. — _vesicutosa, H. Coquand. Mon. Ostrea, Terr. Crét., p. 152, pl. lix,
fies. 4—7.
1871. — — F. J. Pictet and G. Campiche. Foss. Terr, Crét. Ste.

Croix (Matér. Pal. Suisse, ser. 5), p. 311, pl. excivy,
fies. 1—6.
— Grypuma vesicutosa, F. Stoliczka. Paleont. Indica, Cret. Fauna S. India,
vol. iii, p. 466, pl. xxxix, figs. 1, 2.
1882. — — G. Sequenza. Atti R. Acead. Lincei, ser. 3, Cl. Sci.
Fis. Math., vol. xii, p. 182, pl. xix, fig. 2.
1890-91. Osrrea vestcunosa, A. Peron. Descript. Brach., etc., Terr. Crét. Tunisie,
p. 126.
1903. --- = R. Fortau. Bull. Inst. Beyptien, ser. 4, vol. iv, p. 290.
2? 1908. Grypnama aff. vestcunosa, F. Favre. Neues Jahrb. fiir Min., ete., Beil.-Bad.
xxv, p. 609.

Non 1864. Osrrea vestcunosa, S. P. Woodward. Geol. Mag., vol. i, p. 112, pl. v, fig. 6.

OSTREA. 379

Description.—Left valve usually thick, very convex, grypheate, more or less
oval, height usually considerably greater than the length; slightly or moderately
inequilateral, sometimes with a rounded ridge extending from the umbo to the
postero-ventral extremity. Posterior part often convex and separated from the
remainder of the valve by a furrow. Umbo sharp, prominent, more or less
incurved, and usually with a small posterior curvature; surface of attachment
generally small. Area and ligament-pit high, straight or with a small backward
curvature. Adductor impression oval or rounded. Right valve thin, concave.
Surface of both valves smooth, except for growth-lines.

Afjinities—This species is closely allied to O. vesicularis, but the umbo is more
pointed, usually less incurved and with a smaller attached surface; the area is
higher, and usually the height of the shell is relatively greater in proportion to its
length. Most of these differences are probably to be accounted for by the small
size of the attached surface.

T'ype.—From the Upper Greensand of Warminster, in the British Museum.

Distribution—Upper Greensand : common in the zone of Schlenbachia rostrata
of Ventnor, Warminster, Dinton and Potterne; rare in the zone of Pecten asper
of Ventnor, Warminster, and Ballard Down (Swanage). Chloritic Marl ot
Compton Bay, Isle of Wight.

5

OsrREA CANALICULATA (Sowerby), 1813. Plate LVI, figs. 2-16.

1813. Cuama canaricuLara, J. Sowerby. Min. Conch., vol. i, p. 68, pl. xxvi, fig. 1
(non Ostrea canaliculata, Sowerby.)
1821. Osrrea cananicunata, M.J. L. Defrance. Dict. Sci. nat., vol. xxii, p. 26.
1827. Osrrea LaTERaLis, S. Nilsson. Petrific. Suecana, p. 29, pl. vii, figs. 7—10.
— CuHama contca, Nilsson. Ibid., p. 28, pl. vin, fig. 4.
1829. GrypHma cANALICULATA, J. de C. Sowerby. Min. Conch., vol. vi, p. 218.
— Exoeyra unpara, Sowerby. Ibid., vol. vi, p. 220, pl. dev, figs. 5—7.
1833. Osrrea LATERALIS, A. Goldfuss. Petref. Germ., vol. ii, p. 24, pl. Ixxxi,
fie. 1.
2? 1834. GrypHma vomer, S.G. Morton. Synopsis Organic Remains Cret. U. States,
p. 54, pl. ix, fig. 5.
1837. Osrrea LATERALIS, W. Hisinger. Lethea Suecica, p. 46, pl. xiii, fig. 1.
— AMPHIDONTE UNDATA, G. G. Pusch. Polens Paliiont., p. 39.
1842. Exoeyra parvuta, A. Leymerie. Mém. Soe. géol. de France, ser. 2, vol. v,
p- 17, pl. xii, figs. 8, 9.
1845-6. Osrrea LATERALIS, H. B. Geinitz. Grundriss d. Verstein., p. 480, pl. xx,
fig, 22.
1846. Exocyra Larerauis, A. BH. Reuss. Die Verstei. der béhm. Kreideformat.,
pt. 2, p. 42, pl. xxvii, figs. 383—47.
1847. Osrrea canaticubara, A. d'Orbigny. Pal. Franc. Terr. Crét., vol. iii,
p. 709, pl. ceeelxxi, figs. 4—8.

376

1850.

? 1852.

1853.

1868.
1869.

1872.

1881.
1882.

CRETACEOUS LAMELLIBRANCHIA.

JXOGYRA LATERALIS, J. Miller. Petref. der Aachen. Kreidef., pt. 1, p. 40.
GrypH@®A unbaAtTA, JT. Brown. Illustr. Foss. Conch., Gt. Britain
and Ireland, p. 149, pl. Ix, figs. 14, 15.
-- CANALICULATA, Brown. Ibid., p. 149, pl. 1xi, fig. 18.
Osrrea caNnaticuLata, A. d’Orbigny. Prodr. de Pal., vol. ii, pp. 139, 170,
255.
— cyrtoma, R. Kner. Denkschr. Akad. Wissensch. Wien., Math.-
: nat. Cl., vol. iii, p. 320, pl. xvii, fig. 11.
— canaLicuLata, F. J. Pictet and W. Roux. Moll. Foss. Gres verts
de Gentve, p. 522,
pl. 1, fig. 2.
— —- J. Morris. Cat. Brit. Foss., ed. 2, p. 173.
ExoGyra LATERALIS, Morris. Ibid., p. 167.
OsTREA LATERALIS, A. v. Strombeck. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xv, p. 110.
Exoecyra Lareratis, H. Drescher. Ibid., vol. xv, p. 357.
OstrEA LATERALIS, B. Lundgren. Paleont. Iakttag. Fiixekalk. Limhamn,
p. 23.
Exocyra LATERALIS, EL. Hichwald. ethea Rossica, vol. ii, p. 398.
Osrrea cananicunata, H. Coquand. Mon. Ostrea, Terr. Crét., p. 128,
pl. xlv, figs. 13, 14; pl. xlvii,
fizs. 7—10; }1. lii, fig. 13; pl. lx,
figs. 13—15.
-- LATERALIS, Coquand. Ibid., p. 96, pl. xviii, fig. 12; pl. xxx,
figs. 10 —14.
Exocyra LATERALIS, F. Riimer. Geol. v. Oberschles., p. 341, pl. xxix,
figs, 4, 5.
OsrreEA LATERALIS, H. Credner. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxii, p. 228.
— cananicunata, I’. J. Pictetand G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal.
Suisse, ser. 5),
p. 305, pl. exciii,
fiys. 4—14.
Exoayra cAananicunata, F. Stoliczka. Palseont. Indica, Cret. Fauna 8.
India, vol. iii, p. 463, pl. xlvin,
figs. 6—8.
Ostrea (Exoeyra) Laterauis, H. B. Geinitz. Das Elbthalgeb. in Sachsen
(Paleontographica, vol.
Xx, pt. 2); p: Lag) pl. xls
figs. 28—35 ; pt. ii, pl.
viii, figs. 15—17.
ExocyrRa LATERALIS, A. Fritsch. Stud. im Geb. béhmisch. Kreideformat.,
ii, Weissenberg. u. Malnitz. Schicht.,
p- 140, fig. 136.
OsrrEA LATERALIS, J. Gosselet. Esquisse géol. du Nord, pl. xvii, fig. 14.
Exocyra tateratis, H. Schréder. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xxxiy, p. 261. >

1890—

1898.

1901.

1902.

OSTREA. 377

Exoeyra canauicunata, G. Seguenza. Atti R. Accad. Lincei, ser. 3, Cl.
Sci. Fis. Math., vol. xii, p. 176.
— LATERALIS, Fritsch. Op. cit., iii, Iserschicht., p. 118.
— cf. LATERALIS, F'. Frech. Zeitschr. d. deutsch. geol, Gesellsch.,
vol. xxxix, p. 153.
OstREA canaticunatTa, A. Peron. Hist. Terr. de Craie S.E. Bassin
Anglo-Parisien, p. 175.
Exoeyra canaricusata, G. Miiller. Jahrb. d. k. preuss. geol. Landesanst.
fiir 1887, p. 401.
Exoeyra barerauis, Fritsch. Op. cit., iv, Teplitz. Schicht., p. 86.
OstreA (Exocyra) Larerauis, O. Griepenkerl. Senon vy. Kénigslutter
(Paleont. Abbandl.,
vol. iv), p. 36.
Exoeyra vaTeratis, EL. Holzapfel. Die Mollusk. Aachen. Kreide (Paleon-
tographica, vol. xxxv), p. 256.
91. Osrrea canaticuLata, A. Peron. Descript. Brachiop., ete., Terr. Crét.
Tunisie, p. 163.
Exoeyra LATERALIS, Fritsch. Op. cit., Priesen. Schicht., p. 102.
OstrEA LaTERALIs, A. Hennig. Geol. Foren. i Stockholm, Forbandl.,
vol. xvi, p. 513.
— (Exoeyra) Lateratts, F'. Vogel. Hollindisch. Kreide, je, sy
Exocyra cf. cananicu.ata, E. Tiessen. Zeitschr. d. deutsch. geul.
Gesellsch., vol. xlvui,
p. 465.
OstrREA caNnaLicuLata, A. J. Jukes-Browne and W. Hill. Quart. Jourv.
Geol. Soc., vol.
lii, p. 149.
— UateraAtis, A. Hennig. Revision Lamellibr. i Nilsson’s ‘ Petrif.
Suecana,’ p. 23.
ExoGyra LATERALIS, Fritsch. Op. cit., vi, Chlomek. Schicht., p. 68.
“= — R. Leonhard. Paleontographica, vol. xliv, p. 50.
— = A. Rutot. Bull. Soc. Belge Géol. Pal. et Hydrol., vol. x,
p: 27.
— canaricurata, ht. B. Newton. Proce. Dorset Nat. Hist. and Antiq.
Field Club, vol. xviii, p. 91, pl.
ui, figs. 7, 8.
OsTREA CANALICULATA, R. Fortau. Bull. Inst. Fgyptien, ser. 4, vol. iv,
p- 292.
ExoGyra LATERALIS, G. Miiller. Mollusk. Untersen. v. Braunschweig u.
Isede (Abhandl. d. k. preuss. geol.
Landesanst., N.F., 25), p. 15, pl. iii,
fio. 2.
-- — O. M. Reis. Geognost. Jahresh. (1897), p. 108.
“= -— A. Wollemann. Jahrb. d. k. preuss. geol. Landesanst.,
vol. xxi, p. 14.
— — H. Imkeller. Paleontographica, vol. xlviii, p. 38.
— — J. P.J. Ravn. Mollusk. i. Danmarks Kridtaflej. I.
Lamellibr., p. 118.

2)

CRETACEOUS LAMELLIBRANCHIA.

<I

1905. Exoeyra Lavrerais, 7’. Wegner. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. lvii, p. 184.
? 1907. GrypHxosTREA VOMER, S. Weller. Cret. Pal. New Jersey, p. 455, pl. xliv,
figs. 6—11.
1909. Osrrea (Exocyra) LarEratis, W. Rogala. Bull. Internat. Acad. Sci.
Cracovie (1909), 2,
p- 691.
1911. Exoeyra nareratis, Fritsch. Op. cit., Koryean. Schiebt., p- 46, fig. 210.
= _- — K. Vogel von Falckenstein. Zeitschr. d. deutsch. geol.
Gesellsch., vol. — lxii,
p. 961.

Description.—Shell generally rather small, usually higher than long, very
inequivalve.

Left valve very convex or inflated; the greatest convexity is between the
umbo and the postero-ventral extremity, and gives in some cases the appearance
of a much rounded carina, behind which the valve is either flattened or slightly
concave ; sometimes there is a posterior wing-like expansion. The ventral
margin is rounded; the lower part of the posterior margin is often slightly
concave, ending above in a point. Umbo usually much incurved, and directed
posteriorly. The ligament pit usually curves posteriorly. This valve is attached
posteriorly to the umbo; the size, shape, and direction of the attached surface
vary in different individuals, and affect the form of the shell in the usual
way. ‘lhe surface of the shell shows growth-lines, and in some specimens
there are numerous, fine, somewhat irregular ridges running parallel to the
margin of the valve. In the interior of the valve a few widely separated growth-
ridges oceur.

Right valve operculiform, nearly flat, or concave or undulating. Umbo very
small, curving spirally forwards. Surface with widely separated ridges running
parallel to the margin of the valve.

Affinities —The Albian and Cenomanian examples of this species were regarded
by Coquand as distinct from those found in the Upper Chalk and named 0. lateralis
by Nilsson; but @Orbigny, Geinitz, Peron, Jukes-Browne, and Hennig have
shown that the forms named /iteralis cannot be separated from those which occur
in earlier beds (canaliculata). Peron states that on the Continent this species
ranges without interruption through all the stages of the Cretaceous, from the
Aptian to the Danian; he also notes its wide geographical distribution. ‘This
species belongs to Conrad’s “genus” Grypheostrea; it has been referred to
(rrypheu by some writers, but more usually to Meogyra; the left valve, except for
the attached surface, is often grypheate in form, while the right valve shows some
resemblance to Hvegyra. Pictet and Campiche consider that O. canaliculata is
closely related to Hvogyra conica; but it seems more probable that it is alhed to

OSTREA. 379

O. vesicularis, the differences being accounted for by the attached surface in the
former being on the posterior side of the shell.

The form with well-developed concentric ridges (Plate LVI, fig. 19), which
is abundant in the zone of Actinocamar quadratus, but ranges from the zone of
Rhynchonella Cuvieri to that of Belemnitella mucronata, has been named QO. canalicu-
lata var. striata.}

Types.—Chama canaliculata, Sowerby, from the Upper Greensand of Shute,
near Warminster, is in the British Museum. 0. lateralis, Nilsson, is from the
Upper Chalk of Sweden. Chama conica, Nilsson, from the Upper Chalk of
Kopinge, Sweden. Hvoyyra wndata, Sowerby, from the Upper Greensand,
Blackdown, cannot be found.

Distribution.—Hythe Beds (Bargate Stone) of Godalming. Lower Greensand
of Faringdon and Brickhill.

Gault of Folkestone and Okeford Fitzpaine. Upper Greensand (zones of
Schlenbachia rostrata and Pecten asper) of the Isle of Wight (Ventnor, Niton,
Compton Bay). Upper Greensand (zone of Schlaubachia rostrata) of Blackdown.
Upper Greensand (Rye Hill Sands) of Warminster.

Chalk Marl (zone of Schleubachia varians) of Chiseldon. Cenomanian of
Wilmington, Devon. Zone of Holaster subglobosus of Fulbourn and Burwell.

Zone of Rhynchonella Cuviert of Harvet (Kent). Melbourn Rock of Hitchin.

Zone of Terebratulina lata of Hampshire, the South Devon coast, and Dover.

Zone of Holaster planus of Culver Cliff and Dover.

Zone of Micraster cor-testudinarium of Pinhay, Borstal, Seaford and Dover.

Zone of Micraster cor-anguinum of Quidhamptom and Northfield.

Zone of Marsupites testudinarius of Taplow. Uintacrinus band of Devizes
Road (Salisbury), Holmwood Park (Keston), and the Thanet Coast.

Zone of Actinocamax quadratus of Kast and West. Harnham, Whaddon, Marwell
(Hants), Compton, Shawford, Fareham, West Meon, Mottisfont, Taplow and
Brighton.

Zone of Belemnitella mucronata of the Dorset Coast, Rogers Whiting Pit
(Fareham) and Alderbury well.

Zone of Ostrea lunata of Trimingham.

Ostrea semiPLana, J. de C. Sowerby, 1525. Plate LVI, figs. 17—19. Plate LVII,
Plate LVIII, figs. 1—5. Text-figures 183—195).

1803. Osrracires sutcatus, J. F. Blumenbach. Specim. archeol. tell., p. 18, pl. i,
fig. 3. (Non. Ostrea sulcata, Born,

1 Rowe, ‘ Zones of the White Chalk. I, Kent and Sussex ‘ad 900), p. 345 ; Griffith and Brydone,
‘Zones of the Chalk in Hants’ (1911), p. 3.

580

~~

1849.

1850.

CRETACEOUS LAMELLIBRANCHIA.

Osrrea, G. Mantell. Foss. 8. Downs, p. 207, pl. xxv, fig. 4.

SEMIPLANA, J. de C. Sowerby. Min. Conch., vol. v, p. 144. pl.
cecelxxxix, fig. 3.
FLABELLIFORMIS, S. Nilsson. Petrific. Suecana, p. 31, pl. vi,
fig. 4.
piicata, Nilsson. Ibid., p. 31, pl. vii, fig. 12.
pusILLA, Nilsson. Ibid., p. 32, pl. vii, fig. 11. (Non pusilla, Brocchi,
1814.)
ALEFORMIS, S. Woodward. Geol. Norfolk, p. 48, pl. vi, figs.
J—3;
tNEQuicostatTa, Woodward. Ibid., p. 48, pl. vi, fig. 4.
FLABELLIFORMIS, A. Goldfuss. Petref. Germ., vol. ii, p. 12, pl.
Ixxvi, fig. 1.
suLcata, Goldfuss. Ibid., p. 13, pl. lxxvi, fig. 2.
ARMATA, Groldfuss. Ibid., p. 13, pl. Ixxvi, fig. 3.
FLABELLIFORMIS, W. Hisinger. Lethwa Suecica, p. 48, pl. xiv,
fig. 1.
puicata, Hisinger. Ibid., p. 48, pl. xiv, fig. 2.
tnconstans, F. Dujardin. Mém. Soc. géol. de France, vol. ii,
p. 229.
FLABELLIFORMIS, H. B. Geinitz. Char. d. Schicht. u. Petref.
des siichs. Kreidegeb., pt. 1,
a UY),
— F. A, Rimer. Die Verstein. d. nord-deutsch.
Kreidegeb., p. 45.
suLcata, Romer. Ibid., p. 46.
ARMATA, Romer. Ibid., p. 46.
macropreRA ? H. B. Geinitz. Die Verstein. von Kieslingswalda,
p. 17, pl. iii, figs. 22—24.
suLcata, Geinitz. Ibid., p. 17.
—— A. EF. Reuss. Die Verstein. der bohm. Kreideformat.,
pt. 2, p. 39, pl. xxviii, figs. 2—4, 8.
FLABELLIFORMIS, Reuss. Ibid., p. 39, pl. xxviii, figs. 5—7, 16, pl.
xxix, figs. 19, 20.
SEMIPLANA, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 747,
pl. eeeelxxxviil, figs. 4, 5.
FLABELLIFORMIS, J, Miiller. Petref. der Aachen. Kreidef., pt. 1,
p- 39.
armata, Miller. Ibid., p. 39.
SEMIPLANA, 7’. Brown. Tllustr. Foss.Conch. Gt. Britain and Ireland,
p. 145, pl. lix, fig. 7.
InzQuICOsTATA, Brown. Ibid., p. 147, pl. 1xi,*, fig. 13.
SEMIPLANA, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in
Deutschland, p. 198.
carinata, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 357 (0.
frons, p. 386, ed. 2),
pl. xxvii, fig. 2.
sEMIPLANA, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 256.

1872

OSTREA. 381

OsrrREA SEMIPLANA, A, Alth. Geogn.-paliiont. Beschreib. v. Lemberg
(Haidinger’s Naturwiss. Abhandl., vol.
ili, pt. 2), p. 254, pl. xiii, fig. 2.
— Bronnt, J. Miller. Petref. der Aachen. Kreidef., pt. 2, p. 69, pl. vi,
fig. 20.

— semrpLana, J. Morris. Cat. Brit. Foss., ed. 2, p. 174.

— ina#qguicosrata, Morris. Ibid., p. 173.

— sEmipLana, J. Miiller. Petref. der Aachen. Kreidef., Supplement,

[eh

_ — R. Drescher. Zeitschr. der deutsch. geol. Gesellsch.,
vol. xv, p. 356.

— suucara, A. Kunth. Ibid., vol. xv, p. 732.

— FLABELLIFORMIS, EZ. Hichwald. Lethea Rossica, vol. ii, p. 368.

— semreLana, H. Coquand. Mon. Ostrea, Terr. Cret., p. 74, pl. xxviii,
figs. I—15; pl. xxxv, figs. 1, 2; pl.
xxxviul, figs. L1O—12.

— cucuxus, Coguand. Ibid., p. 52, pl. xvii, figs. 19—21.

— .icHENIFoRMIS, Coguand. Ibid., p. 91, pl. xxxvii, figs. 17—19.

— Merceyi, Coquand. Ibid., p. 93, pl. xxviii, tig. 22; pl. xxix, figs.

3

8—14.
— Peroni, Coquand. Ibid., p. 95, pl. xxxv, figs. 3—5 ; pl. xxxviii, figs.
5—9.

— acanrHonota, Coquand. Ibid., p. 103, pl. xxxviii, figs. 1—4.
— suucara, F. Rimer. Geol. v. Oberschles., p. 343, pl. xxix, fig. 3.
— cucutus, C. Schliiter. Neues Jahrb. fiir Min., ete., p. 951.
— semrpLana, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal.
Suisse, ser. 5), p. 321.
— — H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto-
graphica, vol. xx, pt. 2), p. 29) pl. viii,
figs. 8—11, 13.
— FLABELLIFORMIS, J. I. Lahusen. Foss. White Chalk of Simbirsk
(Imper. Russ. Min. Corps
Instit.), pt. 2, p. 250, pl. v,
fig. 3.
— (A.necrryonta) sutcara, D. Brauns. Zeitschr. f. d. gesammt.
Naturwiss., vol. xlvi, p.
393.
— semipLtana, A. Fritsch. Stud. im Gebiete der béhm. Kreide-
format. i, Weissenberg. u. Malnitz.
Schicht., p. 141, fig. 138.
— suxneara, C. Barrois. Ann. Soc. géol. Nord, vol. v, p. 408.
Auecrryonta suntcata, H. Schrider. Zeitschr. d. deutsch. geo]. Gesellsch.,
vol, xxxiv, p. 261.
OstREA SEMIPLANA, Fritsch. Op. cit., iii, Iserschicht., p. 121, fig. 97.
— FRONS, Fritsch. Ibid., p. 121, fig. 96.
armata, J. Bohm. Verhandl. nat. Vereines preuss. Rheinl., vol.
xlii, p. 76.
50

382

CRETACEOUS LAMELLIBRANCHIA.

1885. ALEcrRYONIA cRIsTA UNGULATA, Bohm. Ibid., p. 75, pl. i, fig. 1.
1888. Ostrea seMIPLANA, A. Peron. Hist, Terr. de Craie Bassin Anglo-Parisien,

1889.

? 1889.

1889.

1890—91.

? 1893.
1894.

1898.

1901.

71902.

p. 179.
Peront, Peron. Ibid., p. 180.
sutcata, G. Miller. Jahrb. d. k. preuss. geol. Landesanst. fiir
1887, p. 400.
SEMIPLANA, EH. Holzapfel. Die Mollusk. Aachen. Kreide (Palwon-
tographica, vol. xxxv), p. 251, pl.
xxvii, figs. 5, 6.
Gouprusst, Holzapfel. Ibid., p. 249, pl. xxviii, figs. 8—18.
Bronnt, Holzapfel. Ubid., p. 250, pl. xxviii, figs. 3—7.
Arata, Holzapfel. Ibid., p. 253, pl. xxviii, figs. 1, 2.
Merceyt, Holzapfel. Ibid., p. 251, pl. xxviii, fig. 4.
SEMIPLANA, Fritsch. Op. cit., iv, Teplitz. Schicht., p. 87.
(AtEectRYoONIA) suLcata, O. Griepenkerl. Senon v. Konigslutter
(Paleont. Abhandl., vol. iv),
p. 33.
SEMIPLANA, A. Peron. Descript. Brachiop., ete., Terr. Crét. Hauts-
Plateaux de la Tunisie, p. 154.
— Fritsch. Op. cit., v, Priesener Schicht., p. 102.
= B. Lundgren. Mollusk. i Mammillatus och Mucronata
zonerna (K. Svenska Vet. - Akad.
Handl., n.¥., vol. xxvi, No. 6), p. 37.
Larva, Lundgren. Ibid., p. 37.
SEMIPLANA, A. Hennig. Geol. Foren. i Stockholm Férhandl., vol.
xvi, p. 514.
cucutus, Hennig. Ibid., p. 516.
Bronnt, F. Vogel. Holliindisch. Kreide, p. 7.
sEMIPLANA, R. Leonhard. Paleontographiea, vol. xliv, p. 51.
— Fritsch. Op. cit., vi, Chlomek. Schicht., p. 68.
= A. Rutot. Bull. Soe. Belge Géol. Pal. et Hydrol.,
vol. x, p. 25.
(Atecrryonta) ARMATA, Rutot. Ibid., p. 23.
sEMIPLANA, A. Hennig. Revision Lamellibr. i Nilsson’s ‘ Petrific.
Suecana,’ p. 9, pl. i, figs. 7, 1O—14, 16,
18, 19.
(ALECTRYONIA) SEMIPLANA, O. M. Reis. Geognost. Jahresh. (1897),
p- 107, pl. iv, fig. 18.
SEMIPLANA, G. Miiller. Molluskenfauna Untersen. v. Braun-
schweig u. Ilsede, p. 8, pl. i, figs. 1—4;
pl. iui, figs, 3, 4.
— A. Wollemann. Jahrb. d. k. preuss. geol. Landesanst.,
vol, xxi (1900), p. 13.
— var. ArmAvA, H. Imkeller. Paleeontographieca, vol. xlviii,
p- 37, pl. i, figs. 3—6.
ef. semipLANA, A. Wollemann. Liimeburg. Kreide (Abhandl. d. k.
preuss. geol. Landesanst., N. F.,
37), p. 49.

OSTREA. 383

1902. Ostrea Merceyt, Wollemann. Ibid., p. 51, pl. iti, figs. 6, 7.
— — sEmIpLANA, J. P. J. Ravn. Mollusk. Danmarks Kridtafl. i,
Lamellibr., p. 113, pl. i, figs. 5,
Uh tek
1903. ALrcrryoniA SEMIPLANA, FE. Dacqué. Paleontographica, vol. xxx, 2, p. 366,
pl. xxxiv, figs. 1—4.
1905. Osrrea semipLana, I’. Wegner. Zeitschr. d. deutsch. geol. Gesellsch., vol.
lvii, p. 177, fig. 10.
— — armara, Wegner. Ibid., p. 179, figs. 11—13.

? 1906. — — UL. Krumbeck. Paleontographica, vol. liii, p. 93.
1908. — Perront, P. A. Peron. Compte Rendu Assoc. France. Avane. Sci.,
vol. xxxvi (1907), p. 307.
1909. — (Atrcrryonta) Peroni, M. Leriche. Ann. Soc. géol. Nord, vol.
XxXvill, p. 67, pl. iii, figs.
20—27.

-— — semiIpLaAna, W. Rogala. Bull. Internat. Acad. Sci. Cracdvie (1909),
2, p. 690.
LOW = = Fritsch. Op. cit., Korycaner Schicht., p. 47, fig. 214.
1911. Anxrcrryonra semiptana, K. Vogel v. Falckenstein. Zeitschr. d. deutsch.

geol. Gesellsch., vol. Ixii, p. 559.

Deseription.—Form of shell extremely variable, depending on the shape, size
and position of the surface to which the left valve is attached. In many specimens
the shell was fixed to a cylindrical object (Belemnitella), but in other cases to a
flat or slightly curved surface.

In the larger, fully grown specimens, in which the attached surface is relatively
small and mainly in front of the umbones, being either parallel or oblique to the
hinge, the shell is more or less triangular, or four-sided, or rounded, and its height
is then often greater than its length (Plate LVII, fig. 7; Text-figs. 183—192).

When the shell is attached to a cylindrical body the length of which is at right
angles to the hinge-line, the height of the shell is, at any rate during the attached
stage, much greater than its length, and the front and back margins are more or
less nearly parallel (Plate LVII, figs. 8, 12), but subsequently the postero-ventral
part may grow in a posterior direction (Plate LVII, fig. 11). When the length
of the attached body is parallel or nearly parallel with the hinge-line, and posterior
to the umbo, the shell becomes much longer than high and extremely inequilateral
(Plate LVII, figs. 1—3). If the attached surface is directed obliquely backwards
from the umbo the shell becomes oblique and inequilateral. In small specimens
having a very small attached surface the shell becomes sickle-shaped and the two
valves similar in form (Plate LVI, fig. 18).

During the period in which the left valve is attached to a cylindrical object the
corresponding part of the right valve takes a similarly convex form and remains
without folds; when the left valve is attached to a flat or slightly curved surface

—

CRETACEOUS LAMELLIBRANCHIA.

183—190, Zone of Belemmnitella mucronata, Norwich.
183—185, richt valve, and interior and exterior of left valve of one individual; Norwich Museum.

Fias. 183—192.—Ostrea semiplana, Sowerby.
186, 187, left and right valves of one individual; Sedgwick Museum. 188, left valve (the right
valve is concave) ; Sedgwick Museum. 189, 190, left and right valves of one individual; Norwich
Museum, No. 2101. 191, 192. Zone of Actinocamaz quadratus, Hast Harnham. Dr, Blackmore's
Collection. Exterior and interior of a right valve. All x §.

OSTREA. 385

the corresponding part of the other valve is nearly flat and smooth (Plate LVIII,
figs. 3—5). In the larger specimens with a relatively small attached surface the
left valve (fig. 188) is more convex than the right, the latter becoming in some
cases nearly flat or even concave. The free part of the shell develops folds.
When the attached surface is relatively small the greater part of both valves
possesses strong radial folds which interlock at the margin of the valves. The
folds have more or less rounded summits, sometimes with small pointed projections,
which occasionally develop into spines. The interspaces are usually broader than
the folds. Well-marked growth-lines run parallel to the folded margin of the
valves,

When only the margin of the shell is free no folds are developed, but the edge
of the shell becomes toothed (Plate LVIL, fig. 12); when a narrow strip is free
numerous small folds appear on it (Plate LVII, fig. 13; Plate LVIII, figs. 1—
4), forming a corrugated border to the smooth attached part of the shell.
Occasionally, even when the greater part of the shell is free the folds are indistinct
(figs. 185—185, 191). The direction of growth of the umbo, area, and ligament-
pit vary according to the position of the attached surface ; they may be in the
plane of the valves, or curve inwards or outwards, sometimes becoming nearly
perpendicular to the plane of the valves of the adult shell. The ligament-pit, area
and umbones may be at right angles to the length of the shell, or may curve
obliquely backwards or occasionally forwards. In some cases the area and
ligament-pit are higher than long, in others longer than high.

The inner margin of the valves near the umbo often shows crenulations or
minute irregular ridges. The form of the adductor impression varies with that of
the shell ; it is vertically elongated when the shell is high, and more rounded when
the shell is longer.

Affinities. —A number of the different forms of this shell have been described
as distinct species, since many writers have failed to recognise that the mode of
growth of the shell is determined mainly by the character and position of the
attached surface. The small sickle-shaped form (Plate LVI, fig. 18), with only a
small surface of attachment and the two valves similar, was named O. pusilla by
Nilsson (1827),! O. aleformis by Woodward (1833, pl. vi, fig. 1), and O. Goldfussi
by Holzapfel (1889). Small forms which were attached for a longer period to a
cylindrical object directed more or less nearly perpendicularly to the hinge (Plate
LVII, figs. 8—11, Plate LVIII, figs. 1, 2) and with the margin of the valve folded
and sometimes extended postero-ventrally were named O. aleformis by Woodward
(1833, pl. vi, fig. 2), O. Bronnt by Miller (1851),? O. Peroni by Coquand (1869).
A form in which the shell was attached to a cylindrical object throughout except

1 Hennig (1897), pl. i, figs. 14, 24.
* See also Hennig (1897), pl. i, figs. 7, 11, 12.

386 CRETACEOUS LAMELLIBRANCHIA.

at the actual edge, which is toothed (Plate LVII, fig. 12), was named O. Mevceyi
by Coquand (1869).' Specimens which were attached to a flat object for a long
period (Plate LVIII, figs. 3—5) were figured as 0. aleformis by Woodward (1833,
pl. vi, fig. 3) and O. semiplana by Sowerby (1825, the smaller figure). Larger
forms with a relatively small portion of the anterior part of the shell attached
to a cylindrical object and with well-developed folds, were named O. inequicostata
by Woodward (1833, pl. vi, fig. 4), O. sulcata by Nilsson (1827),? O. jlabelliformis
by Nilsson (1833),? and O. semiplana by Sowerby (1825, the larger figure) (Plate
LVII, fig. 7; Text-figs. 186, 187,193). The forms like O. aleformis and O. Merceyi
are common inthe upper zones. QO. carinata, Sowerby (in Dixon, 1850), is a young
form of O. semiplana. O. armata, Goldfuss, is recognised by Coquand and by
Miller as a form of O. seimiplana in which the ribs have become spiny. 0.
licheniformis, Coquand, is a form in which the valves have a rounded outline.

Fig. 193.—Ostrea semiplana, Sowerby. Zone of Belemnitella mucronata, Hartford Bridge, Norwich. Dr. Rowe’s
Collection. Exterior and interior of a left valve. x

O. acanthonota, Coquand, is a large form in which the ribs tend to become spiny.
QO. avcotina, Stoliczka, is closely allied to, and may be, as maintained by Peron,
identical with O. semiplana. O. Reboudi, Coquand (= O. plicatuloides, Coq.) and
O. Janus, Coquand, are regarded by Peron as forms of O. semiplana.

The close resemblance between the crenulations on the inner margin of the
dorsal part of the valves in O. semiplana and in O. vesicularis, and the occasional
presence of fine radial ribs on the right valve of O. semiplana, suggest that these
two species are rather closely related.

Remarks.—Vhe radial folds are usually stronger in examples from the zone of
Belemnitella mucronata than in those from the lower zones. Occasionally the left
umbo is exogyriform (Plate LVIT, fig. 1 /), but this depends merely on the position
of the attached surface.

1 See also Holzapfel (1889) and Wollemann (1902).
2 Hennig (1897), pl. i, fig. 18.
3 Hennig (1897), pl. i, fig. 16.

OSTREA. 387

Ty pes.— Ostracites sulcatus, Blumenbach, from the Senonian of Salzberg near
Quedlinburg, is stated by Hennig to be in the Natural History Museum, Berlin.
Ostrea sp. Mantell, from the zone of Micraster cor-anguinum of Southerham near
Lewes, and O. semiplana, Sowerby, from the zone of Belemnitella mucronata of
Norwich, are in the British Museum. 0. aleformis, Woodward, and O. inequicostata,
Woodward, are from the zone of B. mucronata of Norwich; the original of fig. 3 of
the former is in the Norwich Museum, but the other specimens cannot be found.
O. carinata, Sowerby (in Dixon), cannot be found.

Distribution.—Probably zone of Terebratulina lata of the South Devon coast.

Zone of Holaster planus of the South Devon coast, Froxfield (Hants.), White
Hill near Goring, and Hart’s Lock Wood.

Zone of Micraster cor-testudinarium of Stevenage, Strood, and Chatham.

Zone of Micraster cor-anguinum of Micheldever, Witherington, Quidhampton,
Foot’s Cray, Southerham (Lewes), Northfleet, New Brompton, Gravesend, and
Litcham, Norfolk.

Zone of Marsupites testudinarius of Ovingdean (Sussex). Uintaerinus band of
Taplow and the Thanet coast.

Zone of Actinocamar quadratus of Kast Harnham.

Zone of Belemnitella mucronata of Ballard Head, Fareham, Clarendon and
Norwich.

Zone of Ostrea lunata of Trimingham.

OsTREA SARUMENSIS, sp. nov. Plate LVIII, figs. 6—9.

Description.—Shell thick, higher than long; slightly, moderately, or consider-
able inequilateral.

Left valve very convex, with the attached surface of variable size. Area large,
high, curved slightly or considerably backwards. Free part of valve with small
‘adial folds, and growth-lamelle. Inner margin with a row of small pits. Right
valve slightly convex, with a large area; surface (except of the earlier part) orna-
mented with numerous small radial ribs separated by linear furrows, and crossed
by growth-lamelle.

Affinities. —The high area and the radial folds of the left valve suggest that
this species may be related to O. semiplana; it also resembles some forms of
O. Boucheroni. More specimens are needed in order to determine satisfactorily the
affinities of this form.

T' ype.—In, Dr. Blackmore’s collection.

Distribution Zone of Actinocamax quadratus of Kast Harnham, near Salisbury.

388

CRETACEOUS LAMELLIBRANCHIA.

Ostrea iNcurVA, Nilsson, 1827. Plate LVIII, figs. 10—15. Plate LIX.

1827.

1833.

1859.

1868.
1869.

? 1870.

1869.

el eye

1878.

1881.

OstrEa incurvA, S. Nilsson. Petrif. Suecana, p. 30, pl. vii, fig. 6.

curvirosrris, Nilsson. Ibid., p- 30, pl. vi, fig. 5.
AcutrirostrRis, Nilsson. Ibid., p. 31, pl. vi, fig. 6.
curvrrostris, A. Goldfuss. Petref. Germ., vol. ii, p. 24, pl. Ixxsii,
fig. 2.
Acurrrostis, Goldfuss. Thid., p. 25, pl. Ixxxii, fig. 3.
TRIANGULARIS, S. Woodward. Geol. Norfolk, p. 48, pl. vi,
figs. 6, 7.
AcutTirosTris, W. Hisinger. Lethea Suecica, p. 47, pl. xiii,
fig. 6.
curvirostrRis, Hisinger. Ibid., p. 48, pl. xiii, fig. 7.
tncuRVA, Hisinger. Ibid., p. 47, pl. xiii, fig. 5.
acurirostris, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 730,
pl. cecelxxxi, figs. 1—3.
TRIANGULARIsS, 7’. Brown. Illust. Foss. Conch. Gt. Britain and
Treland, p. 148, pl. 1xi*, figs. 9, 10.
curvirostris, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 255.
Acurrrostris, d’Orbigny. Ibid., p. 256.
curvirostris, A. Alth. Geogn.-pal. Beschreib. v. Lemberg
(Haidinger’s Naturwiss. Abhandl.,
vol. ii, pt. 2), p. 254, pl. xii,
fig. 38.
acutrrosrris, Alth. Ibid., p. 254.
— , O. curvrrostris, J. Morris. Cat. Brit. Foss., ed. 2,
p. 173.
curvirostris, J. Miller. Petref. Aachen. Kreideformat., Supplement,
Paid
— E. Bichwald, Wethea Rossica, vol. 11, p. 384.
— H. Coquand. Mon. Ostrea, Terr. Crét., p.67, pl. xxxv,
figs. 16—22.
AcuTrIROsTRIS, Coquand. Ibid., p. 75, pl. xxxv, figs. 8—15, pl. xxxvi,
figs. 1—5.
TRINACRIA, Coquand. Ibid., p. 64, pl. xxxv, figs. 23, 24,
acutirostris, H. Credner. Zeitschr. d. deutsch. geol. Gesellsch., vol.
XX, p. 227.
corvirostris, EB. Favre. Moll. Craie de Lemberg., p. 162.
acuTirostris, J’. Stoliczka. Paleont. Indica, Cret. Fauna S.
India, vol. iii, p. 471, pl. xlv,
figs. 1—6.
curvirostRis, G. Behrens. Zeitschr. deutsch. geol. Gesellsch., vol.
xxx, p. 260.
Acurirosrris, R. Ltheridge. In Penning and Jukes-Browne,
Geol. Cambridge, p- 146, pl. iii,
figs. 5, 6.

OSTREA. 389

1881. OsTREA ACUTIROSTRIS var, INFLEXA, Etheridge. Ibid., p. 146, pl. iii,

figs. 7, 8.
1888. — curvirostris, A. Peron. Hist. Terr. de Craie 8.E. Bassin Anglo-

Parisien, p. 173 (partim).
1889. — -- O. Griepenkerl. Senon. v. Konigslutter (Palont.
Abhandl., vol. iv), p. 34, pl. ii,

pike dl
1891. _ — J. Bihm. Paleontographica, vol. xxxviil, p. 92, pl. iv,
fig. 5.
— — acurrrosrris, Bihm. Ibid., p. 92, pl. iv, fig. 11.

1894. — = B. Lundgren. Mollusk. i mammillatus och mucronata

zonerna, p. 39.
== — cvurvirosrris, Lundgren. Ibid., p. 40.
= — scanrensis, Lundgren. Ibid., p. 40.
— — curvirostris, A. Hennig. Geol. Foren. i Stockholm Foérhandl.,
vol. xvi, p. 514.
— — acurrrostris, Hennig. Ibid., p. 514.
1895. — curvrrostris, F. Vogel. Holliindisch. Kreide, p. 5.
— — acuTrrosrRis, Vogel. Ibid., p. 5.
-- — scaniensis, Vogel. Ibid., p. 6.
1897. — usncurva, A. Hennig. Revis. Lamellibr. i Nilsson’s “ Petrif.
Suecana,” p. 11, pl. i, figs. 15, 17, 21—
23, 25—28.
— acurrrostris, F. Nétling. U. Cret. (Maestrichtian) Mari Hills
(Paleont. Indica, ser. xvi, vol. i),
p. 37, pl. ix, figs. 1, 9.
1899. — “= G. de Alessandri. Paleont. Italica, vol. iv, p. 198.
1901. — curvrrostris, H. Imkeller. Paleontographica, vol. xlviii, p. 37.
— — acurirostris, Imkeller. Ibid., p. 37.

? 1902 — — A. Quaas. Paleontographica, vol. xxx, 2, p. 184,
pl. xxi, fig. 11.
— — — BE. Dacqué. Ibid., p. 363.
= — u«ncurva, J.P. J. Ravn. Mollusk. i Danmarks Kridtafl., I, Lamellibr.
p. 112, pl. iui, fig. 4.
1906. -- — E. Bise. Senon. Cardenas (Bol. Inst. geol. México, No. 24),
p. 42, pl. 1, fig. 5.
1908. — curvrirostris, A. Peron. Compte Rendu Assoc. Frang. Avance.

Sciences, vol. xxxvi (1907), p. 306.
a= — _ M. Leriche. Ibid., p. 338 (parti).
1909. — rncurvA, W. Rogala. Bull. Internat. Acad. Sci. Cracovie (1909),
2, p. 691
2, p. 691.

Description—Shell thin, usually higher than long; its form very variable,
depending on the character and size of the attached surface.

The left valve is flat when attached throughout to a flat surface ; concave when
attached to a convex surface; convex when attached to a concave surface or

when attached to only a small object near the umbo ; irregular when attached to an
51

390 CRETACEOUS LAMELLIBRANCHIA.

irregular surface. When the marginal part is free it grows more or less nearly
vertically upwards from the attached surface. When entirely fixed the valve may
be nearly symmetrical, but has usually a posterior curvature ; when attached by a
small area it usually grows backwards and becomes more or less sickle-shaped.
The hgament-pit and umbo are straight in the nearly symmetrical forms; in the
curved forms they are bent or arched more or less considerably backwards, but
occasionally forwards.

The right valve is slightly convex when the entire left valve is attached to a
flat object ; more convex when it is attached to a convex object ; nearly flat when
it is attached to a concave object or when attached near the umbo only ; irregular
and undulating when the attached surface is irregular. The outline of the valve
and the curvature of the ligament-pit and umbo vary according to those of the left
valve. The surface of the right valve sometimes shows concentric ridges, especially
near the umbo, and when well preserved there are numerous, small, irregular,
radiating ridges. The inner margin of the valve on each side of the umbo has
small, transverse, somewhat irregular rounded ridges. The form of the adductor
impression varies with the shape of the shell.

Affinities —Hennig (1897) has shown clearly that the differences between
Nilsson’s O. ineurva, O. curvirostris and O. acutirostris are due to the mode of
growth, whichis determined by the character and size of the attached surface ; and
for this species Hennig selects the name O. wneurva.

O. triangularis, Woodward, which was named 0. trinacria by Coquand, is a
form in which the entire left valve is attached to a flat surface; in the type this
valve is fixed to a small portion of a large Inoceramus (Plate LIX, fig. 14). O.
diepanon, Wollemann,! closely resembles the forms like O. triangularis, and should
probably be regarded as a synonym of O. incurva. Gryphea globosa, Woodward,”
is included in this species by Coquand, but in the absence of the type it is difficult
to give a definite opinion. D’Orbigny and Peron also include QO. conirostris,
Goldfuss. Peron (1888, 1908) regards 0. Wegmanniana, d’Orbigny, as a form of
O. incurva. O. subuncinella, Bohm,* appears to be closely allied to O. incurva.
O. Rabelaisi, Coquand,* from Meudon, resembles closely some forms of O. incurva
(Plate LIX, figs. 12—14), and should probably be included in that species.

Some specimens of O. ‘ncwrva resemble the early parts of O. semiplana before the
development of the radial folds.

Types.—Nilsson’s types came from the Upper Chalk of Sweden. O. triangularis,

1 *Tjimeberger Kreide’ (1902), p. 49, pl. vii, figs. 6, 7. Rogala, ‘ Bull. Internat. Acad. Sci.
Cracovie’ (1909), 2, p. 691, pl. xxviii, fig. 16.

2 ‘Geol. Norfolk ’ (1833), p. 52, pl. vi, fig. 8 (from Marham).

3 « Paleontographica,’ vol. xxxviii (1891), p. 93, pl. iv, figs. 9, 10.

4 «Mon. Ostrea, Terr. Crét.’ (1869), p. 66, pl. xxxvii, figs. 26, 27.

OSTREA. 391

Woodward, from the zone of Belemnitella mucronata of Norwich, is in the Norwich
Museum (Plate LIX, fig. 14).

Distribution—Chalk Marl (zone of Schlanbachia varians) of Burham and
Dover."

Totternhoe Stone (zone of Holaster subglobosus) of Burwell.

Zone of Rhynchonella Cuviert of White Nothe (Dorset), Peter’s Pit (Burham)
and Dover.

Zone of Terebratulina lata of Branscombe, Warnford (Hants) and Beachy
Head.

Zone of Micraster cor-anguinum of Quidhampton, New Brompton, and Grays.

Zone of Marsupites testudinarius of Devizes Road (Salisbury), Taplow and West
Wickham. Uintacrinus band of the Thanet coast.

Zone of Actinocamae quadratus of Kast and West Harnham, West Meon, Mottis-
font, Soberton and Winterbourne (Berks).

Zone of Belemnitella mucronata of Alderbury, Clarendon and Norwich.

Osrrea Bovcneront, Coquand, 1859. Plate LX, figs. 1—15.

1859. Osrrea Boucurront, H. Coguand. Bull. Soc. géol. de France, ser. 2, vol.
xvi, p. L007.

1862. — TEVESTHENSIS, Coquand. Géol. Pal. reg. sud. Province Constantine,
p. 227, pl. xix, figs. 7—13.
1869. — Bovcurront, Coguand. Mon. Ostrea, Terr. Crét., p. 85, pl. xxxi,

figs. 1—3; pl. xxxvii, figs. 1—16; pl.
xxxvill, fig. 20.

39051 — — A. Peron. Descript. Brach., ete., Terr. Crét. Tunisie,
p. 142.
1898. — — G. Miller. Mollusk. Untersen. v. Braunschweig u.

Tisede (Abhandl. d. k. preuss. geol.
Landesanst., N.F., 25), p. 11, pl. iii,
figs. 5—9.

Description —Shell variable in form, usually considerably higher than long,
with the anterior and posterior margins generally diverging gradually from the
umbo. Often the shell is more or less nearly symmetrical, but may be irregular,
and with the ventral part expanded.

Left valve very convex, with the anterior and posterior parts sloping rapidly from
the flank to the margin. The flank is flattened or moderately convex. Umbonal
region usually narrow and pointed. The attached surface is at the umbo and is
usually rather small but sometimes large ; when large the height of the shell may
be relatively small, and the form of the left valve more or less semi-cylindrical. In

! Specimens of Ostrea found in the Upper Greensand of Haldon resemble closely O. incurva.

592 CRETACEOUS LAMELLIBRANCHIA.

the larger specimens a posterior wing-like part is developed, and may be separated
from the remainder of the valve by a furrow. The surface is marked with
erowth-rings.

Right valve thin, slightly convex or nearly flat ; umbo small, with the marginal
part sometimes growing upwards at a considerable angle with the earlier part.
Surface nearly smooth.

Affinities —The English specimens agree closely with the figures given by
Miiller, and fairly well with some of the smaller examples figured by Coquand ;
but the larger forms, in which the height of the shell is relatively less, have not
been found in this country.

Specimens in which the attached surface is larger than usual and the height of
the shell relatively less (Plate LX, figs. 14, 15) resemble some forms of O. vesicu-
lavis, and there seems to be almost a complete passage between these two
species; this resemblance has already been noticed by Peron in specimens found
in the Lower Senonian of Tunis.

The right valve of small specimens is similar to that of the forms of O. ticurva
in which the posterior curvature of the umbo is shght.

The form from Tebessa (Constantine), named O. tevesthensis by Coquand, was
subsequently identified by that author with O. Boucheroni, and that identification
has been supported by Peron. O. lowvillei, Coquand,' from Algeria, resembles
the forms of O. Boucheroni which have a short and Inigh shell.

Remaris.—In England the specimens now referred to O. Boucheroni have been

hitherto identified as O. Wegmanniana, d’Orbigny,’

but the latter species is
regarded by Peron’ and by Leriche,* as a synonym of O. ineurva (p. 388). So
far as I have been able to make out the characters of O. Wegmanniana from the
figures of @Orbigny and Coquand and from the examination of a single right
valve, I am inclined to accept the view of Peron and Leriche.

This species is often gregarious ; most of the English examples are of rather
small size, and the left valve is much more frequently found than the right valve.

T'ype—From the Lower Senonian of Lavalette (Charente), said to be in the
Eeole des Mines, Paris.

Distribution.—Zone of Holuster planus of Hitchin. Recorded by Rowe from
the Isle of Wight.

Zone of Micraster cor-anguinum of Whitway (Hants), Farningham Road, Preston
near Faversham, Gravesend, Charlton, and Loam Pit Hill (Lewisham).

10; and ‘ Mon.

1 «Geol. Pal. reg. sud. Province Constantine’ (1862), p. 232, pl. xxu, figs. 9
Ostrea, Terr. Crét.’ (1869), p. 89, pl. xxi, figs. 3—6, pl. xxiv, figs. 7—11.

2 «Pal. Frang. Terr. Crét.,’ vol. iii (1847), p. 749, pl. eccelxxxviii, figs. 6—8. Coquand, op. cit.
(1869), p. 53, pl. iv, figs. 9-11, pl. xxiii, figs. 11—14. Alessandri, ‘ Pal. Italica,’ vol. iv (1899), p. 198.

5 «Hist. Terr. Craie, 8.E. Bassin Anglo-Parisien’ (1888), p. 173.

4 «Compte Rendu Assoc. Frang¢. Av. Sci.,’ 1907, pt. 2 (1908), p. 338.

OSTREA. 393

Zone of Marsupites testudinarius of Farnborough, Ropley, 'l'aplow, and Brighton.
Recorded by Rowe from the Sussex and Thanet coasts.
Uintacrinus band of Devizes Road (Salisbury) ; Odeham, Alresford, and Itchen

Abbas (Hants); Margate.

Zone of Actinocamax quadratus of Bullington, Ropley, Wield, Andover, and

Rottingdean.

Osrrea LuNAvA, Nilsson, 1827. Plate LX, figs. 16—19. Plate LXI, figs. 1—6.

1816.

oma.

1837.
1849.

1854.
1869.

r 1870.

1884.

1885.

1894.

1895.
1897.

1907.

——

OstREA caNnaLicuLata, J. Sowerby. Min. Conch., vol. ii, p. 81, pl. exxxv,

fig. 1. (Non canaliculata, Sowerby,
1813).
LtunaTa, S. Nilsson. Petrif. Suecana, p. 31, pl. vi, fig. 3.
— A. Goldfuss. Petref. Germ., vol. ii, p. 11, pl. Ixxv, fig. 2.
nasuta, S. G. Morton. Synop. Org. Remains Cret. U. States, p. 51,
pl. ix, fig. 6.
MESENTERICA, Morton. Ibid., p. 51, pl. ix, fig. 7.
LuNATA, W. Hisinger. Letheea Suecica, p. 49, pl. xiv, fig. 4.
— T. Brown. IWlustr. Foss. Conch. Gt. Britain and Ireland,
p. 147, pl. lu*, figs. 20, 21.
LARVA, J. Morris. Cat. Brit. Foss., ed. 2, p. 173.
unGuLATA, H. Coquand. Mon. Ostrea, Terr. Crét., p. 58 ( partim),
pl. xxxi, figs. 6—8 (? 9, 10).
Lunata, H. Credner. Zeitschr. d. deutsch. geol. Gesellsch , vol.
xxii, p. 227.
(Avecrryonta) Larva, C. A. White. Ostreidze of N. America (4th
Ann. Rep. U.S. Geol.
Survey), p. 296, pl. xii,
figs. 2—5, ? 6 (not 7—9).
LARVA Var. NASUTA, Rk. P. Whitfield. Brach. and Lamellibr. Raritan
Clays (Mon. U.S. Geol.
Surv., vol. ix), p. 34, pl. iii,
figs. 3, 4.
LtuNnATA, A, Hennig. Geol. Foren. i Stockholm Férhandl., vol. xvi,
p. 515.
(AvectryontA) LuNATA, F’. Vogel. Holliindisch. Kreide, p. 10.
LuNAtTA, A. Hennig. Revis. Lamellibr. i Nilsson’s “ Petrific.
Suecana,”’ p. 14.
nasuTa, S. Weller. Cret. Pal. New Jersey, p. 447, pl. xliii, figs. 7, 8.
MESENTERICA, Weller. L[bid., p. 446, pl. xliii, figs. 9—14.

Description.—Shell inequivalve, elongated between the umbo and the posterior
extremity, curved regularly, usually sickle-shaped.

Left valve moderately or slightly convex, the part near the umbo being more
convex than the later part. Umbo small, usually curved posteriorly, with, in nearly

39-4 CRETACEOUS LAMELLIBRANCHIA.

all cases, a very minute surface of attachment; on each side of the umbo is a
wing-like or ear-like extension. The early part of the shell is smooth except for
concentric lines or ridges and occasionally fine radial furrows; in the adult the
anterior and ventral marginal parts develop broad rounded folds. The stage at
which the folding begins and the size and number of the folds, vary in different
individuals. Small folds sometimes occur on the posterior wing-like part. The
ligament-pit is sometimes straight but usually curves posteriorly.

Right valve at first smooth and nearly flat, occasionally slightly concave, but
afterwards becoming folded like the left valve. Umbo very small.

Affinities—Most writers, following the example of Coquand, have united
O. lunata, Nilsson, with O. wigulata (Schlotheim),’ regarding the former as a
young stage of the latter. Hennig (1894, 1897) and Vogel (1895), however, do not

* Knorr, ‘ Recueil. Monum. Castast. Pctrificat.,’ vol. ii (1768), p. 180, P. II, pl. Dvii, figs. 5, 6.
Bruguitre, ‘Hist. nat. Vers et Mollusques (Encycl. méthod.), Planches,’ vol. iv (1827), pl. clxxxviii,
figs. 4,5. Faujas-St.-Fond, ‘Hist. nat. Mte. Ste. Pierre’ (1799), p.-150, pl. xxiii, fig. 6. Ostracites
ungulatus, v. Schlotheim, in Leonhard’s ‘ Taschenb. fiir Min.,’ vol. vii, pt. 1 (1813), p. 112; O. crista
meleagris, Schlothem, ibid., p.112. O. larva, Lamarck, ‘ Animaux sans Vert.,’ vol. vi (1819), p. 216;
O. doridella, Lamarck, ibid., p. 210. ? O. falcata, Morton, ‘Amer. Journ. Sci.,’ vol. xvii (1850),
p. 284; vol. xvii (1830), pl. iii, figs. 19, 20. O. larva, Goldfuss, ‘ Petref. Germ.,’ vol. 11 (1833), p. 10,
pl. Ixxv, fig. 1. ? O. falcata, Morton, ‘Synop. Org. Rem. Cret. U. States’ (1834), p. 50, pl. iii, fig. 5
Alectryonia acrodonte, Fischer de Waldheim, ‘Bull. Soc. Imp. Nat. Moscou,’ vol. viii (1834—5),
p. 116, pl. v, fig. 2. O. larva, d’Orbigny, ‘ Pal. Frane. Terr. Crét.,’ vol. ii (1847), p. 740, pl. cecelxxxvi,
figs. 4, 5, 8 (26, 7). O. larva, Miller, ‘ Petref. der Aachen. Kreidef ,’ pt. 1 (1847), p.39. 0. tegulanea,
Forbes, ‘ Trans. Geol. Soc.,’ ser. 2, vol. vii (1846), p. 156, pl. xviii, fig. 6. O. ponticeriana, d’Orbigny,
‘Voy. Pol. Sud et ’Océanie. Atlas Géol.’ (1847), pl. viii, figs. 45, 46. ? O. larva ?, Kner, ‘ Kreidemerg.
v. Lemberg’ (1850), p. 30, pl. v, fig. 4. O. wrogalli, Quenstedt, ‘ Handb. d. Petrefactenkunde’ (1852),
p. 499, pl. xl, fig. 24. O. larva, Beyrich, ‘ Zeitschr. deutsch. geol. Gesellsch.,’ vol. iv (1852), p. 153,
pl. iv, fig. 3. ? O. frons, Kner, ‘ Denkschr. Akad. Wiss. Wien, Math.-nat. Cl.,’ vol. 11 (1852), p. 319,
pl. xvii, fig. 10. ? O. larva, Favre, ‘ Moll. Foss. de la Craie de Lemberg’ (1869), p. 160. O. wngulata,
Coquand, ‘ Mon. Ostrea, Terr. Crét.’ (1869), p. 58 (partim), pl. xxxi, figs. 4, 5, 12—15. O. (Alec-
tryonia) ungulata, Stoliczka, ‘Cret. Fauna S. India,’ vol. iii (1871), p. 470, pl. xlvii, figs. 3,4. O. larva,
Lartet, ‘Ann. Sci. géol.,’ vol. iii (1873), p. 59. Alectryonia larva, Schroder, ‘ Zeitschr. d. deutsch.
geol. Gesellsch.,’ vol. xxxiv (1882), p. 262. O. (Alectryonia) larva, White, ‘ Ostreide of N. America’
(1884), p. 296, pl. xli, figs. 7—9. O. uwngulata, Peron, ‘Hist. Terr. de Craie S.E. Bassin Anglo-
Parisien’ (1888), p. 178. O. (Alectryonia) larva, Griepenkerl, ‘Senon. v. Konigslutter’ (‘ Palont.
Abhandl.,’ vol. iv, 1889), p. 33. O. ungulata, Holzapfel, ‘ Mollusk. Aachen. Kreide’ (‘ Palzeonto-
eraphica,’ vol. xxxv, 1889), p. 250. Alectryonia ungulata, Newton, ‘Quart. Journ. Geol. Soe.,’ vol.
xlv (1889), p. 333, pl. xiv, fig. 12. O. wngulata, Peron, ‘ Descript. Brach., ete., Terr. Crét. Tunisie’
(1890—91), p. 185. O. wngulatu, Bohm, ‘ Paleontographica,’ vol. xxxviii (1891), p. 91. A. wngulata,
Newton, ‘Journ. Conch.,’ vol. viii (1896), p. 136. O. (Alectryonia) wngulata, Notling, ‘U. Cret.
(Mestrichtian) Mari Hills’ (‘ Paleont. Indica,’ ser. xvi, vol. i, 1897), p. 38, pl ix, figs. 4,5. ? O. ef.
larva, Quaas, ‘ Paleontographica,’ vol. xxx, 2 (1902), p. 187, pl. xxi, fig.12. O. (Alectryonia) ungulata,
Boule and Thevenin, ‘Annal. Paléont.,’ vol. i (1906), p. 48 [6], pl. i, fig. 5. A. larva, Krumbeck,
‘ Paleontographica,’ vol. liii (1906), p. 96, pl. vii, fig. 10. O. (Alectryonia) wngulata, Petho, ibid.,
vol. lii (1906), p. 185, pl. xii, fig. 1.

EXOGYRA. 395

accept this view, and consider that O. lunata is a distinct species. They have
studied a large series of specimens agreeing with Nilsson’s type, and do not find
any transitions between O. lunata and 0. ungulata. After examining a large
number of specimens of QO. lunata from Trimingham and comparing them with
foreign examples and figures of O. wigulata, I am led to accept the conclusions of
Hennig and Vogel. From the character of the margin of the shell these specimens
appear to be fully grown individuals and they are not associated with any
examples agreeing with Schlotheim’s species. In O. uwngulata the early part of
the shell resembles the adult of O. lunatu, but subsequently it becomes more
elongate and develops much deeper folds on the posterior as well as on the anterior
margin, consequently the valves become much deeper and more nearly equal than
in O. lunata. Since the folding starts at a later stage in O. lunata than in O. wigu-
lata, it is difficult to see how individuals of the former could ever develop into the
latter as has been supposed by some writers.

Some of the small, sickle-shaped forms of O. semiplana show some resemblance
to O. lunata, but their attached surface is usually larger and their folds are smaller
and more numerous and occur on the posterior as well as the anterior margin.

Remarks.— Mr. Brydone has found a few examples of O. lunata in which the
left valve is entirely attached to the surface of echinoids.

Types.—O. canaliculata, Sowerby, from Trimingham, isin the British Museum.
0. lunata, Nilsson, is from the Ahus-sandstone. Hennig states that the figure
given by Nilsson does not correctly represent the folds.

Distribution.—Upper Chalk (zone of Ostrea lunata) of Trimingham, Norfolk.

Genus —Exoeyra, 1’. Say, 1820.
(‘ Amer. Journ. Sci.,’ vol. ii, p. 43).

Exocyra sinuata (Sowerby), 1822. Plate LXI, fig. 13. Text-figs. 194—-214.

1821. GrypHxa Counont, M. J. LD. Defrance. Dict. Sci. nat., vol. xix, p. 534.
— — DumeriLu, Defrance. Ibid., p. 535.
1822. — stnvata, J. Sowerby. Min. Conch., vol. iv, p. 43, pl.7eccxxxvi
(non Ostrea sinuata, Lamarck, 1819).
— — aguita, A. Brongniart. In Cuvier’s Ossem. Foss., vol. ii, pp.
332, 614, pl. ix, fig. 11.

1829. _ stnvata, J. Phillips. Geol. Yorks., p. 122, pl. ii, fig. 28.
—- DxoGYRA L&vIGATA, Sowerby. Min. Conch., vol. vi, p. 220, pl. dev, fig. 4.
1833. -= aguina, A. Goldfuss. Petref. Germ., vol. ii, p. 36, pl. Ixxxvii,

fig. 3.

5

396

CRETACEOUS LAMELLIBRANCHIA.

OstTREA FALCIFORMIS, FP’. A. Rimer. Die Verstein. nord-deutsch. Ool.-Geb.,
p- 59.
AMPHIDONTE AQUILA, G. G. Pusch. Polens Paliont., p. 38.
Exoeyra stnuata, A. Leymerie. Bull. Soe. géol. de France, vol. xi, p. 121
(vars. subsinuata, ete., p. 124).
— — F. A. Rimer. Die Verstein.d. nord-deutsch. Kreidegeb.,
p. 47.
— unpaATa, Rimer. Ibid., p. 47.
-- sINuATA et suBsInUATA A. Leymerie. Mém. Soe. géol. de France,
vol. v, pp. 16, 17, 28,
pl. xii.
GRYPH#HA SINUATA vars, LEVIGATA, SUBSINUATA, CouLoNI, EH. Forbes.
Quart. Journ. Geol. Soe., vol. i, p. 250.
Exoayra stnuata, A. Leymerie. Statist. géol. et min. de Aube, pl. vi,
fig. 1.
os suBsINUATA, Leymerie, Ibid., pl. vii, fig. 3.
— — var. AQuILINA, Leymerie. Ibid., pl. vii, fig. 4.
OstreA Counont, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 698,
pl. eeeelxvi, figs. 1—4; pl. ececlxvii,
figs. 1—3.
— aguiua, A. d’Orbigny. Ibid., p. 706, pl. eccelxx, figs. 1—4.

Exoeyra srnuata, A. d’Archiac. Mém. Soe. géol. de France, ser. 2, vol. ii,

p- 313.
GrypHma sinuata, 7’. Brown. LIllustr. Foss. Conch. Gt. Brit. and Ireland,
p. 149, pl. Ix, fig. 5.

— aquita, Brown. Ibid., p. 150, pl. 1xi*, figs. 17—19.
— Le&vieata, Brown. Ibid., p. 149, pl. lx, fig. 17.
Exoayra aquita, J. Ewald. Zeitschr. d. deutsch. geol. Gesellsch., vol. ii,

p. 470.
Ostrea aguita, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de
Gentve, p. 520, pl. xlviii,
fies. 1, 2.
Exoeyra stnuata, J. Morris. Cat. Brit. Foss., ed. 2, p. 167.
OstrEA Coutont, G. Cotteau. Moll. Foss. de l’Yonne, p. 122.
— aquita, Cotteau, Ibid., p. 122.
— Covunont, F. J. Pictet and E. Renevier. Foss. Terr. Aptien (Matér.
Pal. Suisse, ser. 1), p.
138.
-- _— J. Vilanova-y-Piera. Mem. geog.-agric. de Castellon, pl.
iii, fig. 24.
— — P. de Loriol. Anim. Invert. Foss. Mt. Saléve, p. 110.
— — de Loriol. Valangin. d’Arzier (Vaud). (Matér. Pal.
Suisse, ser. 4), p. 51.
Exoeyra aquina, 2. Hichwald. Lethxa Rossica, vol. ii, p. 399.
Osrrea Covutont, P. de Lorioland V. Gilliéron. Urgon. infér. de Landeron,
p. 24.
— agua, H. Coquand. Mon. Ostrea, Terr. Crét., p. 158, pl. 1xi, figs.
4—9,

1869.

1870.

1871.

1884.

1900.

? 1908.

? 1904.

EXOGYRA. ; 397

OstrEa Couront, Coquand. Ibid., p- 180, pl. Ixy, fig. 10 ; pl. Ixxi, figs. 8—10 ;
pl. Ixxiv, figs. 1—5; pl. Ixxv, figs. 1—6, 22.
-— — LL, Dieulafait. Bull. Soc. géol. France, ser, 2, vol. xxvii,
p- 431.
— — FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Mater. Pal.
Suisse, ser. 5), p.287,
pls. elxxxvii, elxxxviii,
excii, fig. 1.
Exoeyra sinuara, J, Phillips. Geol. Yorks., Part i, ed. 3, p. 244, pl. ii,
fig. 23.
-- SUBSINUATA, Phillips. Ibid., p. 244.
Osrrea Couront, G. Bohm. Zeitschr. d. deutsch, geol. Gesellsch., vol. xxix,
p- 231.
AitostREON LATIssimum, FE. Bayle. Explic. Carte géol. France, vol. iy,
pt. 2, Atlas, pl. exxxix, figs. 1—3.
-- consoBrinus, Bayle. Tbid., pl. exxxix, fig. 4.
-- Covutont, Bayle. Ibid., pl. exl, figs. 1, 2.
— Aguizinum, Bayle. Ibid., pl. exl, figs. 3—5.
OstrEA (Hxoeyra) Covront, W. Keeping. Foss., ete., Neoe. Upware and
Brickhill, p. 100.
— — — O. Weerth. Fauna d. Neocom. im Teuto-
burg. Walde (Palexont.
Abhandl., vol. ii), p. 55.
Exoeyra aquita, C. A. White. Foss. Ostreidw of N. America (4th Ann.
Rep. U.S. Geol. Surv.), p. 304, pl. liii,
figs. 1, 2.

— Coutont, H. Trautschold. Nouv. Mém. Soe. Imp. Nat. Moscou,
vol. xv, p. 188.

— stnvata, G. W. Lamplugh. Quart. Journ. Geol. Soc., vol. xly,

_p. 615.

— Counont, O. Behrendsen. Zeitschr, d. deutsch. geol. Gesellsch.,
vol. xliii, p. 419.

Ostrea (Exocyra) Counont, G. Maas. Ibid., vol. xlvii, p. 270.
Exocyra Coutoni, A. Wollemann. Ibid., vol. xlviii, p- 831.
— sinuata, R. B. Newton. Proc. Dorset Nat. Hist. and Antiq.
Field Club, vol. xviii, p. 74, pl. ii,
figs. 2, 3.
— aquiLa, K. Gerhardt. Neues Jahrb. fiir Min., ete., Beil.-Bd. xi,
p- 175, pl. iv, fig. 10.

_ Covutont, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u.
holland. Neocoms (Abhandl. d. k.
preus. geol. Landesanst. n.F., pt.31),
p. 8, pl. i, fig. 1.

—_ cf. Coutont, W. Paulcke. Neues Jahrb. fiir Min., ete., Beil.-Bd.

xvii, p. 291.
— Covront, EB. Dacqué. Beitr. Paliont. u. Geol. Osterr.-Ungarns u.
d. Orients, vol. xvii, p. 14, pl. ii, figs. 6—8.
52

398 CRETACEOUS LAMELLIBRANCHIA.

1905. Exoeyra Coutont, EH. Harbort. Fauna d. Schaumburg - Lippe’schen
Kreidemulde (Abhandl. d. k.
preuss. geol, Landesanst., N.-F.,
45), p. 30.
1907. — — O. Haupt. Neues Jahrb. fiir Min., etc., Beil.-Bd.
xxiii, p. 211.

1908. -- — A. A: Stojanof. Ann. géol. et min. Russie, vol. x,
je LUIS}
!
i
hd
Wiis
4 if \
/ 4 (|
/ feR
+ ae
/ rT
/ a
ey
i fj
fi ‘
| ea <

Fia. 194.—Ezogyra sinuata (Sow.) Hythe Beds, Sevenoaks. Sedgwick Museum, Cambridge. Left
valve. x 4.

Description—Shell with subtrigonal, subquadrate, oval or rounded outline ;
often large and massive. The posterior margin is truncated; in the early stages of
growth it is either nearly straight or slightly concave; later it becomes more
concave, with an angular projection at its dorsal and at its ventral end; in large
specimens this margin usually becomes more rounded. The anterior and ventral
margins usually form a convex curve. In large specimens the postero-dorsal
margin is sometimes nearly straight. In many small, and in some large specimens,
the height of the shell is distinctly greater than the length, but in others, particu-
larly large forms, the height and length are nearly equal. In some of the high
forms the shell is considerably arched, the posterior part being concave.

Left valve moderately or very convex. Umbo often relatively small, usually
spiral, with a moderate or large backward curvature. The surface of attachment is

EXOGYRA. 399

Fias. 195—198.—Evogyra sinuata (Sow.). Left valves. 195,197,198, Sedgwick Museum. 196, Mr.
Lamplugh’s Collection. 195, Hythe Beds, Hythe. 196, Speeton Clay (zone of Belemnites lateralis),
Speeton. 197, Tealby Limestone, Claxby. 198. Ferruginous Sands, Atherfield. All x }.

4.00 CRETACEOUS LAMELLIBRANCHIA.

Fras. 199—203.—Ewogyra sinuata (Sow.). Sedgwick Museum. 199, 200, right and left valves of one
specimen; Lower Greensand, Atherfield. 201—203, left valves. 201, 202, Tealby Limestone,

Claxby. 203, Claxby Ironstone, Donnington. All x j.

EXOGYRA. 401

behind the umbo and is usually of small or moderate size. A carina extends in a
curve from the umbo towards the postero-ventral extremity, and sometimes bears
coarse tubercles or spiny projections; it is at first strong, and may be continued to
the postero-ventral margin of the valve, which is then angular; but in large
specimens it often becomes indistinct during the later stages of growth and may
ultimately disappear. Usually the carina is angular at first and becomes rounded
later, but it may be angular throughout or rounded throughout; sometimes it
divides the valve into two nearly equal parts, but usually the anterior is larger
than the posterior part. The former is convex; the latter is flattened or concave
or undulating, and its slope to the posterior margin is often gradual, but may be
steep or even perpendicular. The surface of the valve bears distinct growth-
lines, and sometimes shows faint radial folds. The curvature of the ligament-pit
varies with that of the umbo.

Right valve usually nearly flat or slightly concave or undulating, but sometimes
very concave. Its outline varies as in the left valve. Umbo small, more or less
considerably spiral. Surface with growth-lines and occasionally with faint radial
ribs. Adductor impression large, oval, usually sub-median.

Afjinities.—By some authors, especially Leymerie and Coquand, the forms
similar to the types of Gryphxa sinuata, Sowerby, and G. aquila, Brongniart,’
have been regarded as specifically distinct from those like Hwogyra subsinuatu,
Leymerie?; but Pictet and Renevier (1858), after studying a large series of
specimens from Switzerland, France, and England, came to the conclusion that it
was impossible to separate these as two species; the same view was maintained by
Pictet and Campiche in 1871, and has been supported more recently by Wollemann
(1900), who has examined a large series of specimens from North Germany.
Pictet, Renevier and Campiche showed that the two forms are not, as Leymerie
maintained, characteristic of different horizons, but occur together, although varying
in abundance at different levels. The study of numerous English and some foreign
specimens leads me to endorse the view first expressed by Pictet and Renevier.
The variation is found to be extremely great, and the different forms are connected
by numerous gradations. It is also noticeable, as Pictet and Renevier pointed out,
that the varieties of subsinuata, some of which were named aquilina, dorsata,
and falcifera by Leymerie, may differ from one another more than they do from
sinuata. The forms of the sinuata (aquila) type are common in the Atherfield
and Hythe Beds, and those of the subsinuata type occur mainly in the zones of
Belemnites lateralis and B. jaculum, but neither is confined to those horizons.

1 See figs. 194, 195, 199, and the figures of Sowerby (1822), Brongniart (1822), Pictet and Roux
(1853), Leymerie (1846), pl. vi, fig. 1.

2 See figs. 202, 203, 206, 212, 214, and Leymerie (1842), pl. xii, figs. 3, 7; (1846), pl. vii,
figs. 3, 4.

402 CRETACEOUS LAMELLIBRANCHIA.

Figs. 204—213.—Exogyra sinuata (Sow). 204, 205, left and right valves of one individual; Hythe
Beds, Hythe; Sedgwick Museum. 206, 207, 210, Claxby Ironstone, Donnington ; Sedgwick
Museum ; 206, 210, left valves ; 207, right valve of 206. 208, 209, Hythe Beds, Hythe. Museum
of Practical Geology, No. 20821. Left and right valves (levigata form). 211, Speeton Clay,
(zone of B. lateralis), Speeton. Mr. Lamplugh’s Collection. Left valve. 212, 213. Speeton Clay,
Speeton. Sedgwick Museum. Left and right valves of one individual. All x §.

EXOGYRA. 403

Eeogyra imbricata, Krauss,' from the Uitenhage Series, is closely allied to L.
Coulont.

Remarks.—The proportion of the height to the length of the shell varies con-
siderably. In some specimens the height is much greater than the length, but in
others the two diameters are nearly equal. In the latter case the left valve is usually
less convex relatively than in the higher and more strongly carinate forms. In the
specimens in which the carina reaches the margin the postero-ventral extremity is
more angular than in those in which it becomes indistinct. The slope of the pos-
terior part of the left valve is gentle in the forms in which the height and length are
nearly equal, but becomes steeper in the higher and more strongly carinate forms,

Fic. 214.—Ezxogyra sinuata (Sow). Speeton Clay (probably zone of Belemnites lateralis), Speeton.
Sedgwick Museum. Left and right valves. x }

4.

and is sometimes, as in the example figured by Phillips (1822), perpendicular to
the plane of the valves (fig. 211). In that type, which is an extreme example, the

umbo is only slightly curved, but this form passes gradually into others with a

strongly curved umbo. Indications of radial folds are seen in some specimens,

but they are less distinct than in some foreign examples.

Some specimens show that the stage in which the posterior margin is sinuous
is preceded by one in which it is only slightly concave (fig. 199). The type of
Gryphea aquila, Brongniart, is a small example of the sinuata form with the carina
continued to the margin. The specimen figured by Pictet and Roux is similar, but
larger, and with the carina becoming indistinct towards the margin; the large

1 “Nova Acta Acad. Cxs. Leop.-Carol. Nat. Cur.,’ vol. xxii (1850), 2, p. 460, pl. 1, fig. 2. Sharpe,

‘Trans. Geol. Soc.,’ ser. 2, vol. vii (1856), p. 197, pl. xxiii, fig. 3. Kitchin, ‘Ann. S. African Mus.,”
vol. vii (1908), p. 77.

404 CRETACEOUS LAMELLIBRANCHIA.

rounded forms (like Sowerby’s sinuata) are older individuals of the same type, and
sometimes attain a height of 8 or 9 inches.

A small, oval, very inequilateral form, with a rounded carina, was named Lvogyra
levigata by Sowerby (1829), and was stated to have come from the Irish Green-
sand. An examination of the type shows clearly that it was not obtained from
that deposit, but from the Hythe Beds; the form of the shell and the character of
the matrix agree perfectly with other examples which have been found in the
Hythe Beds (figs. 208, 209).

The examples from the Lower Greensand of Upware, which were referred by
W. Keeping to Hxogyra Couloni, probably belong to this species, but the specimens
seem to me too few and not sufficiently perfect to enable the identification to be
made with certainty.

In England Sowerby’s name (sinwata) has been generally used for this species,
but Defrance’s name (Couloni) has been adopted by foreign writers; the former is
used here since, although Defrance’s name has priority, the description was
scarcely sufficient for identification and was not accompanied by either a figure
or a reference to a figure.

Types.—Gryphea Couloni, Defrance, from the neighbourhood of Neuchatel.
G. sinuata, Sowerby, from the Hythe Beds of Ashford, and EL. levigata from the
Hythe Beds, in the British Museum. G. aquila, Brongniart, from the Upper Aptian
of the Perte du Rhéne. 4G. sinuata, Phillips, from the Speeton Clay, in the York
Museum. LHwogyra subsinuata, Leymerie, from the Neocomian of the Aube.

Distribution.—Atherfield Beds of Atherfield, Compton Bay and Sevenoaks.
Ferruginous Sands of Atherfield and Shanklin. Hythe Beds of Hythe, Lympne
and Maidstone. Folkestone Beds of Folkestone. Mammillatus bed of Okeford
Fitzpaine (Dorset). Speeton Clay (zones of Belemmnites lateralis, B. jaculum and B.
brunsvicensis) of Speeton. Claxby Ironstone (zone of B. lateralis) of Donnington.
Tealby Limestone (zone of B. brunsvicensis) of Claxby.

Exoeyra TuBeRcuLIFERA, Koch and Dunker, 18387. Plate LXI, figs. 7—11.

1835. Exocyra sprrauis, F. A. Riimer. Verstein. nord-deutsch. Oolith.-geb. p. 65
(partim), (non E. spiralis, Goldfuss).

1837. — TUBERCULIFERA, I’, C. L. Koch and W. Dunker. Nord-deutsch
Oolith.-geb., p. 54; pl. vi, fig. 8.
? 1839. — suppLicaTa, I’. A. Rimer. Verstein. nord-deutsch. Oolith.-geb.,
Nachtrag., p. 25, pl. xviii, fig. 17.
1841. — — Rémer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p. 47.
— TUBERCULIFERA, Ftiémer. Ibid., p. 48.
1842. — suppLicaTa, A. Leymerie. Mém. Soc. géol. de France, ser. 2,

vol. v, p. 18, pl. xi. figs. 4—6.

1845.

1847.

1853.

1854.

1855.
1858.

1868.

1869.

1871.

1906.

EXOGYRA. 405

GRYPH#®A HARPA vars. SUBPLICATA et sEmIPLICATA, FE, Forbes. Quart.
Journ. Geol. Soc., vol. i, p. 250, pl. ili, fig. 12:
Osrrea Bousstneauuri, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii,
p. 702, pl. eecelxvin, figs. 6—9
(non figs. 1—3 = O. Minos,
Coquand).
_— HARPA, I’. J. Pictet and W. Roux. Moll. Foss. Grés verts de Gentve,
p. 526, pl. xlix, fig.2.
Exoegyra Harpa, J. Morris. Cut. Brit. Foss., ed. 2, p. 166.
Osrrea Boussineautrit, G. Cotteau. Moll. Foss. de l’Yonne, p. 121.
— Bovssrneauuti, F. J. Pictet and E. Renevicr. Foss. Terr. Aptien
(Matér. Pal. Suisse, ser. 1), p. 140, pl. xix,
fie. 5.
= P. de Loriol. Valangien d’Arzier (Matér. Pal.
Suisse, ser. 4), p. 50, pl. ini,
figs. 14—16.
= — P. de Loriol and V. Gilliéron. Urgon. infér. Lan-
deron, p. 26, pl. i, fig. 23,
pl. ii, figs. 1—4.
—- — H. Coquand. Mon. Ostrea, Terr. Crét., p. 161
(partim), pl. Ixiv, figs. 8—13.
_ TUBERCULIFERA, Coquand. Ibid., p. 189, pl. Ixiii, figs. 8, 9; pl. xvi,
figs. 12, 13; pl. lxx, figs. 9—13.
= — F. J. Pictet and G. Campiche. Foss. Terr. Crét.
Ste. Croix (Matér. Pal.
Suisse, ser. 5), p. 280,
pl. clxxxvi, figs. 1—11.
-- Bousstnecauttit, W. A. Ooster. Protozoe Helvetica, vol. ii, pp.
106, 127, 141, pl. xvi, figs. 5—7.
— (Exoeyra) sprrauis, O. Weerth. Die Fauna des Neocom. im
Teutoburg. Walde (Palgont.
AbhandL., vol. ii), p. 56, pl. ix,
figs. 13, 14 (? 12).
Exo@yRA TUBERCULIFERA, QO. Behrendsen. Zeitschr. d. deutsch. geol.
Gesellsch., vol. xliv, p. 25.
— SUBPLICATA, Behrendsen. Ibid., p. 26.
~ ao G. Maas. Ibid., vol. xlvii, p. 270.
— sprraLis, Maas. Ibid., p. 270.
— TUBERCULIFERA, A. Wollemann. Ibid., vol. xlviii, p. 882.
— Bousstncautti, K. Gerhardt. Neues Jahrb. fiir Min., ete.,
Beil.-Bd. xi, p. 175, pl.i, fig. 6.
— TUBERCULIFERA, Wollemann. Die Biv. u. Gastrop. d. deutsch. u.
holliind. Neocoms (Abhandl. d.
k. preuss. geol. Landesanst., N.F.,
pt. 31), p. 18.
—- — Wollemann. Jahrb. d.k. preuss. geol. Landes-
anst. u. Bergakad., vol. xxvii,

p. 264.

406 CRETACEOUS LAMELLIBRANCHIA.

Non 1842. Exoayra Boussrneautti, A. d’Orbigny. Voy. dans l’Amerique Mérid.,
vol. iii, pt. 4, pl. xviii, fig. 20;
p. xxi, figs. 8,9 (=O. Minos,
Coquand).

Description.—Left valve very convex, elongated between the umbo and the
postero-ventral extremity, more or less considerably arched, with a sharp carina
curving from the umbo to the extremity and becoming less prominent on the later
part of the valve. Behind the carina the valve is concave or flattened, in front of
it regularly convex. Umbo more or less considerably spiral. From the carima a
number of rounded radial ribs extend to the margin, but are indistinct or absent
on the posterior part of the valve; these give a corrugated margin to the valve ;
the ribs are crossed by well-marked growth-ridges. Inside the valve, at a short
distance from the margin, is a band of transverse crenulations. Adductor impression
large, oval, submedian, or rather near the posterior margin. The attached surface
may be small or large; when large, the marginal part (except the posterior) grows
vertically upwards from the support and bears ribs. Right valve nearly flat, with
growth-lines ; umbo smali, spiral.

Affinities. —This species is related to H. Minos, Coquand,' but in the latter
radial ribs occur on the right valve. It seems probable that HW. tuberculifera has
been derived from a small form of HL. sinuata. A small example (Plate LXI, fig.
13) whichagrees with the lxvigata type of EH. sinwata, except for the presence of
radial ribs, seems to connect that species with H. tuberculifera.?

T'ypes—The type of Koch and Dunker is a right valve from the Neocomian of
the Elligser Brink; the surface of this specimen has a tuberculate appearance
because it is encrusted by another organism.’ Later authors have been able to
identify it with the forms named H. subplicata, Romer, and E£. Boussingaulti,
d’Orbigny, of which good figures have been published. The specimens figured by
Forbes, which have a large surface of attachment, are from Atherfield, and are now
in the Museum of Practical Geology (No. 25984).

Distribution.— Lower Greensand :—Perna-bed of Atherfield, Redcliff (Sandown),
and East Shalford; Crackers of Atherfield; Ferruginous Sands of Shanklin;
Hythe Beds of Lympne.

1 D’Orbigny, ‘Pal. Frang. Terr. Crét.,’ vol. iii (1847), pl. cecelxviii, figs. 1—3 ; Coquand, ‘ Mon.
Ostrea, Terr. Crét.’ (1869), p. 183, pl. Ixiv, figs. 1—3, pl. Ixxiii, figs. 48, pl. xxiv, figs. 14, 15; Pictet
and Campiche, ‘ Foss. Terr. Crét. Ste. Croix’ (‘ Mater. Pal. Suisse,’ ser. 5, 1871), p. 278, pl. clxxxv;
Wollemann, ‘ Bivaly. u. Gastrop. deutsch. u. hollind. Neocoms’ (1900), p. 15; Miller, ‘ Deutsch.-
Ost-Afrika,’ vol. vii (1900), p. 548, pl. xxiii, fig. 1, text-figs. 46, 47.

2 See also Leymerie (1842), pl. xi, fig. 4.
3 The name tuberculifera is consequently inappropriate, but has {been retained by several authors.

EKXOGYRA. 4.07

Exocyra conica (Sowerby), 1813. Text-figures 215—242.

1813. Cuama conrca, J. Sowerby. Min. Conch., vol. i. p. 69, pl. xxvi, fig. 3.

— — REcuRVATA, Sowerby. Ibid., p- 69, pl. xxvi, fig. 2.

-- — Puicata, Sowerby. Ibid., p. 70, pl. xxvi, fig. 4.

— — HALioTorpEa, Sowerby. Ibid., p. 67, pl. xxv, figs. 1—5.

1829. Exocyra contca, J. de (C. Sowerby. Thbid., vol. vi, p- 219, pl. dev, figs.

figs. 1—3.
? 1838. — conica, A. Goldfuss. Petref. Germ., vol. ii, p- 36, pl. Ixxxvii,

fig. 1.
— — SUBCARINATA, Goldfuss. Thbid., p- 37, pl. Ixxxvii, fig. 4.
— _ unpata, Goldfuss. Ibid., p. 35, Ixxxvi, fig. 10.
— — HALIOTOIDEA, Goldfuss. Tbid., p. 38, pl. Ixxxviii, fig. 1.
1837. AmpHiponrE contca, G. G. Pusch. Polens Paliont., p.39.
_ — HALIOTOIDEA, Pusch. Ibid., p. 38.
1839. Exoeyra cornu ARIETIS, E. HALIOTOIDEA et E. aquina, H. B. Geinitz.
Char. d. Schicht. u. Petref. des siichs.
Kreidegeb., pt. 1, p. 20.
1840. — PLICATULA, Geinitz. Ibid., pt. 2, p. 84.
P 1846. _ — A. H. Reuss. Die Verstein. der bohm. Kreideformat.,
pt. 2, p. 44, pl. xxxi, figs. 5—7.
1847. Osrrea contca, A. @Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 726,
pl. ceeelxxviii, figs. 5—8 ; pl. eceelxxix,

figs. 1—3.
= —_ Ravuiyiana, d'Orbigny. Tbid., p. 708, pl. eecelxxi, figs. 1—3.
= — -HaviotipEa, @’Orbigny. Ibid., p. 724, pl. eecelxxviii, figs. 1—4.

1849. GrypHma conica, T. Brown. Illustr. Foss. Conch. Gt. Brit. and Ireland,
p- 149, pl. lx, fig. 3.
— — HALIOTOIDEA, Brown. Ibid., p. 149, pl. lx, figs. 6—9.
1850. Osrrea contca, A. @ Orbigny. Prodr. de Pal., vol. ii, rey 1A
— — Ravurytana, d’Orbigny. Ibid., p- 139.
— — HaviotrpEa, d’Orbigny. Ibid., p. 171.
— Exoeyra Ravrrniana, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 357,
(EB. haliotoidea, p. 386, ed. 2),
pl. xxvii, fig. 7.
— — conica, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in
Deutschland, p. 202.
1853. Osrrea Ravuintana, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de
Genéve, p. 521, pl. 1,
fig. 1.
1854. Exoayra conica, J. Morris. Cat. Brit. Foss., ed. 2, p. 166.
— — HALIOTOIDEA, Morris. Ibid., p. 166.
1859. —~ _— T. Wiltshire. Red Chalk of England (Geol.
Assoc.), p. 16, pl. ii, fig. 6.
— OstreEa vesicuLaris, Wiltshire. Ibid., p- 16, pl. ii, fig. 5.
1863. — conica, A. v. Strombeck. Zeitschr. d. deutsch. geol. Gesellsch., vol.
xv, p. 109.

408

? 1868.

? 1871.

? 1885.

CRETACEOUS LAMELLIBRANCHIA.

Osrrea contca, A. Briart and F. L. Cornet. Meule de Bracquegnies (Mém.
cour. et Mém. des. Sav. ¢trangers, vol. xxxiv), p. 49,
pl. iv, figs. 3, 4.
“= HALIOTOIDEA, Briart and Cornet. Ibid., p. 45, pl. iv, figs. 5, 6, 8.
Exoeyra contca, I’. Hichwald. ethea Rossica, vol. ii, p. 400.
Osrrea conica, H. Coquand. Mon. Ostrea, Terr. Crét., p. 160, pl. lin,
figs. 1—7.
— HattoTipga, Coquand. Ibid., p. 144, pl. 1, figs. 8—10; pl. lu, figs.
1i—17.
— Ravrrntana, Coquand. Ibid., p. 157, pl. 1xi, figs. 1—3.
ExoGyra HALIOTOIDEA, F. Stoliczka. Palweont. Indica, Cret. Fauna 8.
India, vol. iii, p. 458, pl. xxxvi,
fig. 7; pl. xxxvii, figs. 1—3.
OstreA Ravuiniana, F. J. Pictet and G. Campiche. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse, ser. 5), p. 307,
pl. exciii, figs. 15, 16.
— contca, Pictet and Campiche. Ibid., p. 302, pl. exciii, figs. 1, 2.
— (Exoeyra) conica, H. B. Geinitz. Das Elbthalgeb. in Sachsen
(Paleontographica, vol. xx, pt. 1),
p. 183, pl. xl, figs. 8—13; pt. 2, pl.
viii, fig. 14.
_ — HALIOTOIDEA, Geinitz. Ibid., p. 184, pl. xli, figs. 1—18.
Exocyra HALIoTOIDEA, A. J. Jukes-Browne. Quart. Journ. Geol. Soc.,
vol. xxxi, p. 296.
-- conica, A. Fritsch. Stud.im Gebiete der bohm. Kreideformat. i.
Weissenberg. u. Malnitz. Schicht., p. 139,
fig. 184.
RHYNCHOSTREON conicuM, FH. Bayle. Explicat. Carte géol. France, vol. iv,
Atlas, pt. 1, pl. exxxviii, figs. 6, 7.
OsrrEeA conica, J. Gosselet. Esquisse géol. du Nord, iii, pl. xvii, fig. 11.
Exoeyra contca, H. Schrider. Zeitschr. d. deutsch. geol. Gesellsch.,
vol, xxxiv, p. 259.
— _— G. Sequenza. Atti R. Accad. Lincei, ser. 3, Cl. Sci. Fis.
Math., vol. xii, p. 176.
— HALIOTIDEA, Seguenza. Ibid., p. 175.
— conica, vars., W. Keeping. Foss., ete., Neoc. Upware and
Brickhill, p. 101, pl. iv, fig. 3.
— — FF. Notling. Die Fauna d. baltisch. Cenoman. (Paleont.
Abhandl., vol. ii), p. 14, pl. ii, figs. 1, 2.

1890-91. Osrrea conica, A. Peron. Brachiopodes ete., Terr. Crét. Hauts-

? 1893.

1895.
a
1909.

Plateaux de la Tunisie, p. 113, pl. xxiii,
figs. 8—10.
Osrrea sp. cf. HALIOToIDEA, R. Michael. Zeitschr. d. deutsch. geol.
Gesellsch., vol. xlv, p. 239.
Exoeyra conica, E. Tiessen. Ibid., vol. xlvii, p. 466.
-— ef. HALIOTIDEA, Tiessen. Ibid., p. 465.
_- conica, R. B. Newton. Trans. Roy. Soe. 8. Africa, vol. i, p. 51,
pl. ui, figs. 8—10.

EXOGYRA. 409

Non 1827. Cuama conica, S. Nilsson. Petrific. Suecana, p. 28, pl. viii, fig. 4.

— 1837. — — WW. Hisinger. Lethea Suecica, p. 63, pl. xix, fig. 4.
? — 1841. Exoeyra conica, F. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb.,
p. 47.
P — 1883. — — A. Fritsch. Stud. im Gebiete d. bohm. Kreidef. in

Iserschicht., p. 117, fig. 92.

Description.—Left valve very convex, with a more or less subtriangular or
semi-oval outline, very inequilateral. Anterior and ventral margins rounded ;
posterior margin oblique, either straight, slightly concave, convex or sinuous, often
forming a rounded angle with the ventral margin. Umbo spiral, curved inwards,
and considerably backwards; the attached surface usually behind the umbo. A
carina, generally distinct but sometimes rounded, extends in a curve from the umbo
towards the postero-ventral extremity. The part of the valve behind the carina
is more or less flattened, and may be concave near the umbo; the part in front of
the carina is regularly convex. In large specimens the postero-ventral part
is more extended and the length of the shell in relation to the height becomes
relatively greater, the postero-ventral extremity is more rounded, and_ the
carina becomes less distinct. The surface of the valve is usually smooth, except
for growth-lines, but in some specimens (wndata form) numerous somewhat
irregular radial ridges are present, either in the neighbourhood of the umbo or
over the entire valve. On the inside of the valve, at a short distance from the
margin, is a band of small transverse ridges and pits which broadens and becomes
more irregular near the postero-dorsal margin. Adductor impression rather near
the postero-dorsal margin, with its upper boundary straight or slightly convex.

Right valve thin, operculiform, often slightly concave, with a small spiral
umbo ; surface nearly smooth; outline varying with that of the left valve.

In the forms described above (conica type), the surface of attachment is
small, but it may be very large so that all the left valve with the exception of a
narrow marginal part is fixed (haliotoidea and Rauliniana types) ; between these
extremes every gradation is found. The free marginal part, which seldom extends
to the posterior border, usually grows nearly vertically upwards from the body to
which the shell is attached. When the attached surface is mainly or entirely
behind the position of the carina, then the free marginal part in front is larger, and
usually the shell is relatively higher and the spire of the umbo less developed, and
in such cases the marginal part sometimes forms an acute angle with the attached
surface.' The character of the surface (flat, concave, convex or irregular) to which
the left valve is attached also influences the form of the shell.

Affinities —The forms of small or moderate size, which are abundant in the

1 See d’Orbigny, pl. eceelxxviii, figs. 1—4.

410 CRETACEOUS LAMELLIBRANCHIA.

Upper Greensand, and of which typical examples were figured by Sowerby in 1829,
have a small surface of attachment, and have been known in this country as Hvogyra
conica (figs. 220—225). <A similar form, but of larger size, is common in the
Chalk Marl (figs. 228, 229), and the Glauconitic Sandstone of Antrim; no line can
be drawn between this and the smaller form of 1. conica, with which it has been
united by most authors (e.g. d’Orbigny, Morris, Coquand, Bayle, Peron) ; examples
indistinguishable from H. conica of the Upper Greensand are associated with the
larger form in Antrim, and on the other hand, some specimens found in the Upper
Greensand of the south of England are of larger size than the majority of examples
and cannot be separated from the larger form of I. conica; but nevertheless the
larger form appears generally to mark a somewhat higher horizon than the
smaller (conica, Sowerby) form.

EL. haliotoidea, Sowerby, from the Upper Greensand (fig. 240), is a small form
of EL. conica with a large surface of attachment, and is connected by intermediate
forms with examples having only a small attached surface. Similarly #. Rauliniana,
@Orbigny (fig. 236—239), from the Gault, Upper Greensand, and Lower Chalk,
is a large form of H. conica with a large surface of attachment and is linked by a
series of gradations (figs. 230—235) to the type with only a small attached
surface. Peron’ has already shown that the large specimens from the Cenomanian
of France figured as H. haliotoidea by @Orbigny and Coquand are only forms of
I. conica modified by having a large surface of attachment; they occur in the
same beds as undoubted examples of 1. conica. In some specimens with a large
attached surface the height of the shell is greater than usual, but this, as pointed
out above, is due to the shell being fixed mainly or entirely by the posterior
slope behind the carina; in such cases the free marginal part forms a sharp angle
with the attached surface. Morris and Jukes-Browne united WZ. haliotoidea and
fH, Kauliniana, and Pictet and Campiche recognised the very close relationship
of these two forms.

Examples from horizons above the Cenomanian have been referred to LH. halio-
toidea by some authors,’ notably Hennig, who has compared the Senonian forms
of Sweden with specimens from the Cenomanian and Gault. Without the oppor-
tunity of examining the Senonian forms I am unable to express any opinion as to

1«Compte Rend. Assoc. frang. Avane. Sci.,’ xxxvi (1908), pt. 2, p. 312.

2 Chama haliotoidea, Nilsson, Petrific. Suecana (1827), p. 28, pl. viii, fig. 3; Hisinger, ‘ Lethwea
Suecicea’ (1837), p. 62, pl. xix, fig. 3. Hxogyra haliotoidea, Reuss, ‘ Die Verstein. d. bohm. Kreideformat.,’
pt. 2 (1846), p. 44, pl. xxvii, figs. 5, 9, 10, pl. xxxi, figs. 9—10; Miiller, ‘Petrefact. Aachen. Kreidef.,
pt. 1 (1847), p. 42; Schroder, ‘Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. xxxiv (1882), p. 260, pl. xv,
fig. 5; Griepenkerl, ‘Palaont. Abhandl.,’ vol. iv (1889), p. 86; Hennig, ‘Revis. Lamellibr. i Nilsson’s
‘ Petrific. Suecana’ (1897), p. 19, pl. i, fig. 20, pl. ii, figs. 3,4; Rutot, ‘Bull. Soc. Belge Géol. Pal. et
Hydrol.,’ vol. x (1897), p. 27, fig. 11.

EXOGYRA.

231

Figs. 215—231.—Exogyra conica (Sow.). 215—226, Upper Greensand. 227—231, Chalk Marl. Sedewick

Museum except 219, 224, 228. 215, 216, Niton; left and right valves. 217,218, Ventnor ; left and
right valves. 219, Haldon; British Museum, No. L. 16860; left valve of ribbed variety. 220—223,
zone of Schlenbachia rostrata, Blackdown; left valves. , right valve of 221. 224, zone of
Pecten asper, Warminster; Bristol Museum; left valve. 5, zone of P. asper, Evershot; left
valve. 226, zone of Schlanbachia rostrata, Dunscombe; left valve. 227, Folkestone: left valve.
228, 229, Blue Bell Hill, Burham; British Museum, No. L. 10382; left valve and dorsal view.
230, 231, Folkestone; left valve and dorsal view. All natural size.

411

412 CRETACEOUS LAMELLIBRANCHIA.

their relationship. Hennig also includes 7. awricularis (Wahlenberg)' in 2. halio-
toidea.

Pictet and Campiche figure and describe examples of HY. conica from the Aptian.
Specimens of Hxogyra from the Lower Greensand of Upware, Brickhill, Faringdon
and Shanklin have been referred to /. conica; in these the carina is more rounded

Fias. 232—242.—Bwogyra conica (Sow.). Sedgewick Museum except 288--240. 232—235, Cambridge
Greensand (base of Chalk Marl). 233, 234, left valves. 232, right valve of 233. 2385, right valve
of 234. 236, 237, zone of Holaster subglobosus, Burwell ; 236, right valve ; 287, anterior view of 236
showing the large size of the attached surface of the left valve. 238, 289, Gault, Folkestone ;
Museum of Practical Geology, No. 20873; 238, right valve; 239, anterior view showing left valve
attached toa flat Inoceramus. 240, Upper Greensand, Devizes. Museum of Practical Geology,
No. 20999. Left valve. 241, 242, Cambridge Greensand; ribbed form with a large surface of
attachment ; 241, left valve; 242, anterior view of 241. All natural size.

than in the common form of the species, but they agree closely with, and seem to
be inseparable from some forms of [. conica from the Upper Greensand (figs.
215—218).

Small specimens with radial ribs (fig. 219), such as the one figured by Goldfuss

1* Petrific. tell. Suec.’ (1821), p. 58. See also Schroder, ‘ Zeitschr. d. deutsch. geol. Gesellsch.,’ vol.
xxxiv (1882), p. 260, pl. xv, fig. 4.

EXOGYRA. 413

as Hi. undata and by d’Orbigny as FH. conica, have not usually been regarded
as distinct from LH. conica.

Pictet and Campiche record H. arduennensis (d’Orbigny)' from the Upper
Greensand of Blackdown, but they doubt whether that form is really distinct from
EH. conica; the chief difference is that in the former the left umbo is less prominent
and less curved.

HH. subconica, Vogel von Falckenstein,® from the Senonian is allied to H. conica.

Types.—The types from the Upper Greensand are in the British Museum.
Chama conica from Chute (Warminster) ; C. recurvata and C. plicata from Haldon ;
C. haliotoidea (figs. 1, 3, 5 are missing) from St. Mary Donhead (Wiltshire). The
specimens of I. conica figured by Sowerby in 1829 from the Upper Greensand of
Blackdown, and the specimen figured in Dixon as 7. Itauliniana from the Lower
Chalk (probably zone of Holaster subglobosus) of Sussex, are in the same Museum.
The specimens from the Lower Greensand of Upware, figured by Keeping, and
those from the Red Limestone of Hunstanton figured by Wiltshire, are in the
Sedgwick Museum.

Distribution.—Probably Lower Greensand of Upware and Faringdon. Lower
and Upper Gault of Folkestone. Lower Gault of the Isle of Wight. Red Lime-
stone of Hunstanton. Upper Greensand (zone of Schlanbachia rostrata) of
Blackdown, Haldon, Dunscombe, Beer Head, Pinhay Cliffs, Niton, Ventnor, etc.
Upper Greensand (zone of Pecten asper) of Evershot, Eggardon Hill, Warminster,
the Dorset coast, and the Isle of Wight. Cambridge Greensand (indigenous and
derived). Chloritic Marl of Compton Bay, Isle of Wight. Chalk Marl (zone of
Schlenbachia varians) of Folkestone, Blue Bell Hill (Burham), Reach and Stoke
Ferry. Cenomanian of Wilmington, Devon, and the South Devon coast. Zone
of Holaster subglobosus of Burham, Holborough, Dover, Arlesey, Burwell and
Fulbourn.

Exocyra coLumBa (Lamarecl:), 1819. Text-figs. 248—248.

1768. G. W. Knorr and J. FE. M. Walch. Recueil Mon. Catastr. Pétrificat.,
VOL@ tiGmpe lade ple Elna:
figs. 1—3.
1802. GrypH#a suporBicuLATA, Lamarck. Systéme Anim. sans Vert., p. 398.
1813. GrypHites RATISBONENSIS, FE. T'. v. Schlotheim. In Leonhard’s Taschen-
buch fiir Min., vol.
vii, p. 105.

“1 «Pal. Franc. Terr. Orét.,’ vol. iii (1847), p. 711, pl. cecelxii, figs. l—4. Pictet and Campiche, ‘Terr.
Crét. Ste. Croix’ (1871), pp. 304, 308, pl. exciii, fig. 3.
2 ‘Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. lxii (1911), p. 560, fig. 1.
54

414.

1819.
1820.
1821.
1822.

CRETACEOUS LAMELLIBRANCHIA.

GRYPH@A coLuMBA, Lamarck. Anim. sans Vert., vol. vi, p. 198.
Grypuites sprratus, EB. T. v. Schlotheim. Petrefactenk., p. 288 (partim).
GrypHma cotumBA, M. J. L. Defrance. Dict. Sci. nat., vol. xix, p. 534.
_— — J. de C. Sowerby. Min. Conch., vol. iv, p. 115,
pl. ceelxxxiii, figs. 1, 2.
GRYPHEA coLuMBA, A. Brongniart. In. Cuvier, Ossemens Fossiles, vol. ii,
pp. 320, 608, pl. vi, fig. 8.
Osrrea couumBa, G. P. Deshayes. Hist. nat. Vers et Mollusques (Eneyel.
m¢thod.), vol. ii, p. 302, Planches,
vol. iv, pl. elxxxix, figs. 3, 4.
Exocyra cotumBa, A. Goldfuss. Petref. Germ., vol. ii, p. 34, pl. Ixxxvi, fig. 9-
— — A.dArchiac. Mém. Soc. geol. de France, vol. ii, p. 185.
GrypHma coLtumBA, F. Dujardin. Ibid., p. 228.
AMPHIDONTE coLuMBA, G. G. Pusch. Polens Paliont., p. 37, pl. v, figs. 1, 2.
Exocyra cotumsa, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs-
Kreidegeb., pt. 1, p. 20.
-- (GrypH#®A) coLtumBa, F. A. Rimer. Die Verstein. d. nord-
deutsch. Kreidegeb.,
p. 46.
— cotumBa, H. B. Geinitz. Grundr. d. Verstein., p. 481, pl. xx,
figs. 19, 20.
—. — A. EF. Reuss. Die Verstein. der béhm. Kreideformat.,
pt. 2, p. 43, pl. xxxi, figs. 1—4.
Ostrea cotumBa, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 721, pl.
eceelxxvii.
_- — d’Orbigny. Prodr. de Pal., vol. ii, p. 171.
Exoeyra cotumsa, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in
Deutsebland, p. 202.

1851-52. Exoayra cotumsa, H. G. Bronn. Lethxa Geogn., vol. ii, pt. 5, p. 270,

1859.

? 1866.

? 1868.

13869.

pl. xxxi, fig. 10.

= — J. Morris. Cat. Brit. Foss., ed. 2, p. 166.
— — J.Ewald. Zeitschr. d. deutsch. geol. Gesellsch., vol. ix,
p. 12.
Ostrea Reaumurt, H. Coquand. Bull. Soc. géol. de France., ser. 2, vol.

xvi, p. 960.
Osrrea cfr. cotumBa, K. A. Zittel. Bivalv. d. Gosaugeb. (Denkschr. d.
k. Akad. d. Wissensch., Wien,
Math.-nat. Classe, vol. xxv, pt. ii),
p. 47 [123], pl. xix, fig. 2.

Osrrea cotumsBa, A. Briart and F, L. Cornet. Meule de Bracquegnies
(Mém. cour. et Mém.
des. Sav. ¢trangers,
vol. xxxiv), p. 46, pl.
iv, figs. 13—15.

Exocyra cotumsa, HE. Hichwald. Lethwa Rossica., vol. ii, p. 404.

OsTREA RATISBONENSIS, H. Coquand. Mon. Ostrea, Terr. Crét., p. 121, pl.

xly, figs. 8—12.

EXOGYRA. 415

21870. Osrrea cotumBa, W. A. Ooster. Protozoe Helvet., vol. ii, p. 57, pl. x,
fig. 18.

-— Exocyra corumsa, F. Rimer. Geol. v. Oberschles., p. 332, pl. xxvi, fig. 1.
1871. Osrrea conumsa, F’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal.
Suisse, ser. 5), p.319.
— Exoeyra susporpicunata, F. Stoliczka. Paleont. Indica, Cret. Foss. S.
India, vol. iii, p. 462, pl.

xxxv, figs. 1—4.

1872. Osrrea (Hxocyra) cotumsa, H. B. Geinitz. Das Elbthalgeb. iv Sachsen
(Paleontographica, vol.
og jum Use, Ul il esl
figs. 4—7.

1877. Exocyra cotumsa, A. Fritsch. Stud.im Gebiete der bdhm. Kreideformat.,

ii. Weissenberg. u. Malnitz. Schicht.,
p. 139, fig. 135.
1878. Ruyncnosrreon Cuapert, HL. Bayle. Explicat. Carte géol. France, vol. iv,
Atlas, pt. 1, pl. exxxviii, figs. 1—5.
1882. Exocyra RATISBONENSIS, G. Seguenza. Atti R. Accad. Lincei, ser. 3, Cl.
Sci. Fis. Math., vol. xii, p. 181,
pl. xix, fig. 1.
1890-91. OsrrEea suBorBicuLaTa, A. Peron. Descript. Brach. etc., Terr. Crét.
Tunisie, p. 119, pl. xxiii, figs.
11—13.
1893. Osrrea cotumsBa, S. Meunier. Le Naturaliste, p. 176, fig. 3.
— Exocyra cotumsa, R. Michael. Zeitschr. d. deutsch. geol. Gesellsch.,
vol. xlv, p. 238.
Pp — — suporBicuLATA, 7. W. Stanton. Colorado Formation (Bull. U.S.
Geol. Survey, No. 106), p.
62, pl. v, fig. 6; pl. vi, figs. 1,
2; pl. viii, fig. 1.

1897. — corumBa, R. Leonhard. Paleontographica, vol. xliv, p. 27.
— _— _— U. Séhle. Geogn. Jahresh. (1896), p. 41.
? 1900. — — G. Miiller. Deutsch-Ost-Afrika, vol. vii, p. 566, pl.
xxiv, fig. 2.
1902. — — P. Oppenheim. Centralbl. fiir Min., ete., p. 500.
1903. Osrrea suBorBIcuLAtTA, R. Fortav. Bull. Inst. Egyptien, ser. 4, vol. iv,
p. 289.

1911. Exocyra cotumsa, 0. Schlagintweit. Neues Jahrb. fiir Min., etc., Beil.-
Bd, xxxiii, p. 111.

Description.—Shell very inequivalve, moderately or rather considerably inequi-

lateral, usually higher than long and more or less ovate in outline, with, in some
cases, the postero-ventral margin somewhat produced.

Left valve inflated, usually with a very small surface of attachment. Umbo

usually prominent, spiral, curved more or less considerably backwards. ‘The

flank of the valve may be regularly convex, or may show a rounded carina

416 CRETACEOUS LAMELLIBRANCHIA.

extending from the umbo postero-ventrally, but this often becomes indistinct in
the later stages of growth ; the posterior part of the valve (behind the carina) is
convex, except the postero-dorsal part near the umbo, which is concave, and here
the margin is more or less concave. The surface of the valve is smooth, except

¥
4
‘
‘
‘
‘

Fias. 248—248.—Kwogyra columba (Lam.). Zone of Pecten asper. 243—245, Evershot. 246—248,
Eggardon Hill. 243—247, left valves. 244, posterior view of 243. 248, right valve and left
umbo of 247. Sedgwick Museum, Cambridge. All x §.

for growth-lines. Right valve flat, or slightly convex or concave, sometimes
undulating. Umbo small, spiral.

Affinities —This species is allied to H. conica, but the carina is less distinct
and more rounded, the posterior part of the left valve is less flattened, and the
spire of the left umbo is better developed.

Remarks.—Since the name given by Lamarck in 1819 (colwmba) has been used
by the majority of later writers it seems better to retain that, rather than attempt
to revive the little-known name given by the same author in 1802.

EXOGYRA. 417

In the Cenomanian of France and other regions where this species is very
abundant it is found to be much more variable than it is in the South of England.
This variation is also seen in the specimens found in the Glauconitic Sandstone
of Antrim. Variation is particularly noticeable in the size of the left umbo, in the
extent of its curvature, the more or less inequilateral character of the shell and in
the distinctness of the carina.'

In the Cenomanian of Algeria and Tunis, specimens, usually known as Ostrea

x

Mermeti, Coquand,’ are extremely abundant and very variable; but Peron, after
comparison with numerous French specimens from the same horizon, refers these
North African forms without doubt to H. columba.

Types.—From the Cenomanian of Le Mans. The specimens figured by Sowerby
are in the British Museum; fig. 1 (upper figure) and fig. 2 are from the Ceno-
manian of Le Mans; fig. 1 (lower figure) is probably from the same locality
although labelled ‘* Northampton.”

Distribution.— Upper Greensand (zone of Schlanbachia rostrata) of Blackdown,
the South Devon and Dorset coasts. Upper Greensand (zone of Pecten asper) of
the South Devon and Dorset coasts, Evershot, Askerswell, Eggardon Hill, Little-
bredy (Dorset) and Warminster. Chloritic Marl of Compton Bay, Isle of Wight-
Cenomanian (Meyer’s beds 11, 12) of Beer Head.

°
Exoeyra pierrata (Sowerby), 1817. Text-figs. 249—252.

1817. Cama pierrata, J. Sowerby. Min. Conch., vol. ii, p. 165, pl. clxxiv, figs.
1—4.
1840. Exoayra sacrniata, H. B. Geinitz. Char. d. Schicht. u. Petref. des sachs.
Kreidegeb., pt. 2, p. 58.
1849. GrypHma piartata, 7. Brown. Lllustr. Foss. Conch. Gt. Brit. and Ireland,
p- 149, pl. lx, fig. 16.
1850. Exoayra piairata. H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in
Deutschland, p. 204.
1854. — = J. Morris. Cat. Brit. Foss., ed. 2, p. 166.
1862. Osrrea Coquannpr, Julien, in H. Coquand, Géo. et Pal. Constantine, pl.
xxxiii, figs. 1O—12.

1 It should be noted that the apparently small size of the left umbo in the specimens figured by
some authors (e.g. Geinitz) is due to the fact that the specimens are internal casts from which the
thick shell has been removed.

2 O. Mermeti, Coquand, ‘ Géol. et Pal. Reg. sud Prov. Constantine’ (1862), p. 234, pl. xxiii, figs.
3—5 ; Coquand, ‘ Mon. Ostrea, Terr. Cret.’ (1869), p. 131, pl. li, figs. l1O—12 ; Lartet, ‘ Annal Sci. géol.,
vol. iii (1878), p. 60, pl. x, figs. 8—16. 0. Larteti, Coquand, op. cit. (1869), p. 153, pl. Ixii, figs. 15,
16. O. Luynesi, Lartet, op. cit. (1873), p. 64, pl. x, figs. 17, 18; Coquand, op. cit. (1869), p. 153,
pl. lxii, figs. 17, 18.

418

CRETACEOUS LAMELLIBRANCHIA.

Fics, 249—252.—Ezogyra digitata (Sow.). Upper Greensand (zone of Pecten asper). Left valves. 249,
near Lyme Regis; British Museum, No. 52. 250, White Nothe; British Museum, No. L.4914. 251,
Evershot; Museum of Practical Geology, No. 20956. 252, Weston, South Devon; Sedgwick
Museum ; convex variety. All x {.

1868. Osrrea piettaTa, A. Briart and F. L. Cornet. Meule de Bracquegnies
(Mém. cour. et Mém. des
Sav. étrangers, vol.
xxxiv), p. 47, pl. iv, figs.

1, 2:
1869. = — H. Coquand. Mon. Ostrea, Terr. Crét., p. 142, pl. xli,
figs. 6B—8.
1871. — _ F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér. Pal.
Suisse, ser. 5), p. 317.

EXOGYRA. 419

1872. Osrrea (Exogyra) piarrara, H. B. Geinitz. Das Elbthalgeb.in Sachsen
(Paleontographica, vol.
xx, pt. 1), p. 184, pl. xl,
fiz. 14.
1882. Exoeyra prerrata, G. Sequenza. Atti R. Accad. Lincei, ser. 3, Cl. Sci.
Fis. Math., vol. xii, p. 180.

Description.— Shell inequilateral, with rounded outline; height and length
often nearly equal.

Left valve moderately, sometimes considerably convex. Umbo spiral, curved
considerably backwards ; the attached surface small, and posterior to the umbo. A
carina, sometimes sharp, sometimes rounded, extends in a curve from the umbo
towards the postero-ventral extremity, and becomes less distinct on the later part
of the valve ; behind the umbo the valve is concave or flattened. A few prominent,
widely separated radial folds are present; some start from the carina, others
begin later, and the ventral part of the carina sometimes becomes replaced by a
fold. The dorsal folds are curved. On the folds strong spine-like projections are
often developed, and form projections at the margin of the valve. Fine growth-
lines occur, and bend over the folds. Right valve nearly fiat.

Affinities.—O. vultur, Coquand,’ resembles this species in its strong folds and
spines, but the left valve is more inflated and the carina less distinct. LH. digitata
shows considerable resemblance to some forms of H. cornu arietis (Nilsson)? from the
Senonian, in which is included /. laciniata (Nilsson).

Except for the strong radial folds /. digitata resembles some of the less convex
forms of 7. sinuwata, from which it may have been derived.

Type-—The types, from the Upper Greensand (zone of Pecten asper) near
Sidmouth, cannot be found.

Distribution.—Upper Greensand (zone of Pecten casper) of Beer, Weston
(Devon), Evershot, and White Nothe (Dorset).

Exoeyra sicmoippa, Reuss, 1844. Plate LXI, fig. 12.

1844. Exocyra siamorpEa, A. FE. Reuss. Geognost. Skizz. Bohmen, vol. ii,
p- 180.
1846. — — A. E. Reuss. Die Verstein. der bbhm. Kreideformat.,
pt. 2, p. 44, pl. xxvii, figs. 1—4.
1*Mon. Ostrea, Terr. Crét.’ (1869), p. 118, pl. xxxix, figs. 1—4. Rhynchostreon vultur, Bayle,
‘ Explicat. Carte géol. France,’ vol. iv (1878), Atlas, pl. exli.
2 Nilsson, ‘ Petrific. Suecana’ (1827), p. 28, pl. viii, fig. 1. Griepenkerl, ‘ Paleont, Abhandl.,’ vol
iv (1889), p. 35, pls. v, vi, vii, figs. 6, 7, Hennig, ‘Revis. Lamellibr. i Nilsson’s Petrific. Suecana’
(1897), p. 21. Chama laciniata, Nilsson, op. cit., p. 28, pl. viii, fig. 2.

120 CRETACEOUS LAMELLIBRANCHIA.

~w

1866. Ostrea (Exoeyra) sp. cfr. stamoiprA, K. A. Zittel. Bivalv. d. Gosaugeb.
(Denkschr. d. k. Akad. Wissensch.
Wien, Math.-nat. Cl., vol. xxxv,
pt. 2), p. 123, pl. xix, fig. 5.

1869. — siemorpEa, H. Coquand. Mon. Ostrea, Terr. Crét., p. 93, pl. xxxiv,
figs. 5—7 bis.
1872. — (Exoeyra) stemorpeEa, H. B. Geinitz. Das Elbthalgeb. in Sachsen

(Paleontographica, vol.
xx, pt. 1), p. 186, pl. xli,
figs. 14—27.

? 1882. Exoeyra cfr. stemoripEa, R. Windmiller. Jahrb. d. k. preuss. geol.
Landesanst. fiir 1881,

p. 30.
1888. a stemMoIpEA, G. Miiller. Ibid. fiir 1887, p. 401.
1911. -- — A. Fritsch. Stud. im Geb. d. bohmisch. Kreidef.,

Korycaner Schicht., p. 46, fig. 209.

Remarks.—The only English specimen I have seen is aright valve collected by
Mr. Ll. Treacher. The strong carina, the concentric ribs on the anterior slope,
the more sinuous and more oblique posterior margin and growth-lines distinguish
this species from the Rauliniana form of H. conica. The inner margin of the
valve is finely crenulate. The types came from the Lower Planer-kalk of Schilling
near Bilin.

Distribution.—Zone of Micraster cor-anguinum of Boxford, Berkshire.1

Family—RADIOLITIDA, Gray.
{Omitted from Vol. IT, p. 210.]

Genus—Dourania, H. Douvillé, 1908.

(‘ Bull. Soe. géol. de France,’ ser. 4, vol. viii, p. 309, and ‘Mém. Soc. géol. de France, Paléont.,’ vol.
xviii, 1910, p. 23.)

Duranta Mortont (Mantell), 1833.

1833. Hippurtres Morton, G. Mantell. Geol. 8.E. England, p. 130.

1836. Contra, Rk. Hudson. Loudon’s Mag. Nat. Hist., vol. ix, p. 104, fig. 19.

1838. SpHmruiires Mortont, J. EH. Gray. Mag. Zool. Bot., vol. ii, p. 228.

1850. Hrepurrres Morvront, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 354
(p. 385, ed. 2), pl.

xxvi, figs. 1, 2, 4.

1 White and Treacher, ‘ Quart. Journ. Geol. Soc.,’ vol. lxii (1906), p. 518.

DURANIA. 4.21

1854. Rapronrres Moroni, J. Morris. Cat. Brit. Foss., ed. 2, p. 160.
Po — sp., Morris. Ibid., p. 160.
1900. Brraproxires Moroni, H. Dowvillé. Bull. Soe. géol. de France, ser. 3,
vol. xxviii, p. 230.

1904. — = Douwvillé. Tbid., ser. 4, vol. iv, p. 174.

1909. Sauvacusta Morronr, A. Toucas. Classific. et Bvolut. des Radiolitidés
(Mém. Soc. géol. de France, Paléont.,

: vol. xvii), p. 92, fig. 59.

1911. Ravionrres Morvont, F. Francke. Zeitschr. d. deutsch. geol. Gesellsch.,

vol. lxiil, Monatsber., p. 357.

Non 1855. -- Morvont, 8S. P. Woodward. Quart. Journ. Geol. Soc., vol. xi,
p- 59, pl. v, figs. 1, 2.
— 1866. — — K. A. Zittel. Bivalv. d. Gosaugeb. (Denkschr. d. k.

Akad. Wissensch,. Wien, Math.-nat.
Cl., vol. xxv, pt. ii), p. 72, pl. xxv,
figs. 1—3.

—— 1903: = == V. Hilber. Jahrb. d. k. geol. Reichsanst., vol. li,

(1902), p. 282.

Description—Lower valve at first conical, afterwards becoming elongate and
cylindro-conical, nearly straight or slightly arched. Longitudinal ribs strong,
angular, sometimes in groups of two or three, crossed by growth-lines. Bands
concave, with fine ribs; the interband convex, usually with strong ribs. Radiating
grooves bifurcate once, twice or more in passing from the inner to the outer
margin. The cellular structure varies in coarseness in different specimens,
and sometimes becomes rather finer towards the outer margin. Upper valve not
known.

Affinities. —One of the specimens figured by Sowerby (Dixon, fig. 3) is distin-
guished from the others by its concave interband with fine ribs and by the narrower
siphonal bands ; it probably belongs to another species.

Remarks.—Fragments which probably belong to this species are moderately
common in the Lower Chalk, and in the Cambridge Greensand,' but good specimens
are rare. Some examples are of considerable size, the largest being a specimen
from the Cambridge Greensand, in which the lower valve has a depth of 21 inches.

Types.—Mantell’s specimens cannot be traced. ‘The examples figured by
Sowerby (in Dixon, figs. 1—4), from the zone of Holaster subglobosus, near Lewes
(probably Glynde), and the specimen figured by Hudson from Lewes, are in the
British Museum.

Distribution.—Cambridge Greensand (base of Chalk Marl). Probably Chalk

1 Another species of Durania is represented in the Cambridge Greensand by a form with broad,
slightly concave bands with fine ribs, and a narrow, strongly concave interband with coarse ribs. The
bands and interband resemble those of some species of Sauvagesia (Toncas, 1909, pl. xvii, figs. 1, 3,6).

ay)

4.22 CRETACEOUS LAMELLIBRANCHIA.

Marl (zone of Schlanbachia varians) of Ventnor and Folkestone. Zone of Holaster
subglobosus of Burham and Lewes. Zone of Rhynchonella Cuviert of Dover.
Zone of Terebratulina lata of Wouldham. Zone of Holaster planus of Morgan’s

Hill, Wiltshire.

Durania sp. cf. austinensis (omer), 1852.

1855. Raproxurres Morront, S. P. Woodward. Quart. Journ. Geol. Soe., vol. xi,
p- 59, pl. v, figs. 1, 2.
1904. Brrapronires Austinensis, H. Douwvillé. Mission Scient. Perse. III,
Btudes géol. iv, Paldéont.,
p. 257.
1909. Sauvagusra austinensts, A Toucas. Classific. et Evolut. des Radiolitidés
(Mém. Soe. géol. de France, Pal-
éont., vol. xvii), p. 96, fig. 64.
1912. Duranta austinensts, C. F. Parona. Mem. R. Accad. Scienze di Torino,
ser. 2, vol. lx, p. 287, pl. ii, fig. 4.

Remarics.—In the specimen from the Upper Chalk figured by Woodward the
siphonal bands are much broader than in Durania Mortoni, and the ribs on the
convex interband are finer and more widely separated. The parts recognised by
Toucas as siphonal bands were regarded by Woodward as the surfaces to which
other individuals had been attached.

This species has been identified with Romer’s Hippurites austinensis from Texas!
by the authors quoted above, but, as Prof. Douvillé now points out, this identifi-
cation must be regarded as uncertain since the essential characters of Rémer’s
species are not yet known.’ The finer structure of the outer layers of the shell
cannot be taken as a distinguishing feature of Romer’s species.

T'ype.—W oodward’s specimens from Roshervyille are in the British Museum.

Distribution.—Zone of Micraster cor-anguinum of Rosherville, near Gravesend.

1 Romer, ‘ Kreidebild. vy. Texas’ (1852), p. 77, pl. vi, fig. 1.

* A few specimens show indications of the ligamental ridge and appear to belong to the genus
Sauvagesia, e.g. British Museum No. 33957 from the zone of Holaster subglobosus of Sussex, and No.
L. 4842 from the Turonian of Dover.

ADDITIONS. 4.25

ADDITIONS AND CORRECTIONS.

Arca, sp. [Vol. I, p. 35.]

Internal casts of a species of Arca have been found in the zone of DBelemnitella
mucronata of Norwich. Two examples are preserved in the Norwich Museum (Nos.
2121, 2122).

Dicranoponta. [Vol. I, p. 53.]

Species of Dicranodontu have now been recognised by Borissjak* in the Jurassic
deposits of Russia. In connection with this genus or subgenus the papers of
Solger* and Schmidt* should be consulted.

CRENELLA orBIcuULARIs (Sowerby), 1836. Plate LXI, figs. 14—17.
[Omitted from Vol. I, p. 105.]

1836. Lucrna? orprcunartis, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp- 241, 341, pl. xvi, fig. 13.

1850. Lucrna orprcunarts, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 162 (partim).

1854. —_ — J. Morris. Cat. Brit. Foss., ed. 2, p. 208.

1866. — — EF’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal. Suisse,
ser. 5), p. 291.

1871. Lucina? orsicunanris, I’. Stoliczka. Paleont. Indica, Cret. Fauna S. India,

vol. ili, p. 252.

Description.—Shell thin, small, oval, higher than long, slightly inequilateral,
regularly convex, with rounded margins. Umbones pointed, with a small anterior
curvature. Lunule and escutcheon not defined. Ornamentation consists of numerous,
equal, regular, radial ribs which curve outwards from the median line of the valve
and are separated by narrow furrows. <A few growthk-rings occur at intervals.

1 “ Pelecypoden Jura-ablager. Europeisch. Russland. IT Arcide,” ‘Mém. Com. géol.,’ N.s., xix
(1905), pp. 29—32, 58—60, pl. iv, figs. 5—13.

2 “Ueber Pseudocucullea, einen neuen Taxodontentypus,” ‘ Zeitschr. d. deutsch. geol. Gesellsch.,’
vol. ly (1903), Monatsber., p. 76.

8 Thid., vol. lvi (1904), Monatsber,, p. 120,

4.24, CRETACEOUS LAMELLIBRANCHIA.

Measuremeits :

Q) @) (3) (4)
Length . Z - ( 67) >: 6) mm,
Height. 8 76 b 6°70° Gs

(1—4) Blackdown.

Affinities—This species has been placed in the genus Lucina by previous
writers, but Stoliezka suggests that it belongs to Limopsis. Although numerous
specimens have been seen, none of them shows the character of the linge and the
adductor impressions satisfactorily, but I think that the species should be referred
to the genus Crenella. OC. inflata (Miller)' from the Senonian of Aachen is a
much more inflated form.

T'ype.—From Blackdown; in the Bristol Museum.

Distribution.—Upper Greensand (zone of Schlanbachia rostrata) of Blackdown,
Haldon, Sidmouth.

SEPTIFER LINEATUS (Sowerby). [Vol. I, pp. 107, 225.]

A specimen from the Utntacrinus band of Devizes Road, Salisbury, has been
found by Dr. Blackmore. The type of Modiola quadrata, Sowerby (in Dixon)
from Sussex is in the British Museum.

Vol. I, p. 117, footnote. The type of Dianchora ? guttata, Sharpe (1853, pl. Vi,
fig. 4), is in the Museum of Practical Geology (Geological Society Collection).

Diayopon Boum, Stolley, 1892.

Grénwall® states that this, or a closely allied form, occurs in the Upper Chalk

of Gravesend and Grays.

Vol. I, p. 152, footnote. For “ Miiller” vead “ Nilsson.” For Ravn “ p. 9,” read
<r Oke

Prcren (Cutamys) prirrannicus, Woods. Plate LXI, fig. 18.
[Vol. I, p. 167, pl. xxi, figs. 1, 2.]

When this species was described only the left valve was known. A specimen
from Bromley with the two valves united has since been found. The right valve

1 Holzapfel, ‘ Paleontographiea,’ vol. xxxv (1889), p. 220, pl. xxv, figs. 17—19.

2 “Geol. Mag.’ 1906, p. 203; Stolley, ‘Die Kreide Schleswig-Holsteins’ (1592), p. 245, pl. vii,
fig. 8; Grinwall, ‘Meddel. fra Dansk. geol. Foren.,’ No. 6 (1900), p. 78, pl. ii, fig. 8.

ADDITIONS. 425

is nearly flat, and the broad radial ribs are much less distinct than on the left
valve; numerous fine concentric ribs are present, and are widely spaced on the
early part of the valve, but become closer together on the later part.

Prerrn (Cniamys) crerosus, Defrance.

Vol. I, p. 179, line 17, delete “ Clarendon and Alderbury (Salisbury).”

Prcrren (ALQuirEcTEN) CAMPANIENSIS, d’Orbigny. [Vol. I, p. 192.]

A specimen of this species has been found by Dr. Rowe in the zone of
Micraster cor-testudinarium of Dover.

Lima (Limea?) sp. Plate LXI, fig. 19.
{Omitted from Vol. IT, p. 52. |

A few examples of a species which resembles Limea granulatissima, Wollemann,'
have been found in the Speeton Clay (zone of Belemuites lateralis) of Speeton.
Only a young individual is figured by Wollemann, so that exact comparison

cannot be made at present.

Sub-genus—Psrvuporrera, Meek.

When describing the species of Pseudoptera (pp. 63-69) I regarded it as a
sub-genus of Pteria. Ligament-pits have not been seen in any English specimens,
but their presence was noticed by Guéranger* and by Peron* and indicates that
Pseudoptera cannot be associated with Pteria, but should probably be regarded as

a sub-genus of Gervillia.

Gervitiia Forpsestana, d’ Orbigny.
[ Vol. II, p. 85, pl. xi, figs. 26, 27; pl. xii, figs. 1—5.]

This species belongs to the sub-genus Hnsigervilleia of Dietrich.

1 «Bivaly. u. Gastrop. d. deutsch. u. holliindisch. Neocoms’ (1900), p. 37, pl. ii, figs. 4, 5.

2 «Album Paléont. de la Sarthe’ (1867), pp. 17, 20, pl. xxii, figs. 9, 10; pl. xxv, figs. 10, 11
Woods, ‘ Paleont. U. Cret. N. Nigeria’ (1911), p. 273, footnote 1.

3 “Descript. Brach. ete., Terr. Crét. Tunisie” (1890—91), p. 288.

* *Centralbl. fiir Min., ete.’ (1910), p. 235.

4.26 CRETACEOUS LAMELLIBRANCHIA.

Asrarte (Ertpuyta) concinna, Sowerby, 1836. Plate XVII, fig. 7 (see p.
116-118).

When describing the species of Astarte the only specimen of A. concinna
known was the type, and I regarded it as probably only an individual variation of
A. striata. Dr. Kitchin' has since found several specimens in the Sandgate Beds
of a pit-sinking at Dover which agree with A. concinna, and he considers that
this should be regarded as a distinct species. Dr. Kitchin also obtained A. (Lriphyla)
striata, Sowerby, from the same place.

CRraASSATELLITES, Sp. [Omitted from Vol IT, p. 180.}

Internal casts of a short subquadrate shell, probably belonging to the genus
Crassatellites, occur in the Chloritic Marl of Maiden Bradley and Devizes.

CRraASSATELLITES ? EQUISULCATUS (Woods), 1897. Plate LXI, figs. 20,21. Plate LXII,
io
[Omitted from Vol. IT, p. 130.]

1897. Arcrica? reursutcata, H. Woods. Quart. Journ. Geol. Soe., vol. liii,

p- 391, pl. xxvii, figs. 6—8.

Deseription.—Shell convex, subquadrate, oblique, very equilateral. Umbones
anterior, pointed, with slight forward curvature. Greatest convexity between
the umbones and the postero-ventral extremity; postero-dorsal part compressed.
Adductor impressions distinct, the posterior one deep. Shell rather thick,
ornamented with numerous concentric ribs, separated by narrow grooves.

Remarks.—The systematic position of this species is uncertain; it appears to
be closely allied to the form from the Chloritic Marl mentioned above.

Type.—In the Sedgwick Museum.

Distribution.-_Chalk Rock of Cuckhamsley, Berkshire.

ANTHONYA, sp. [Vol. II, p. 180.]

A portion of a left valve of Anthonya closely resembling A. cantiana has been
found in the Upper Greensand (zone of Pecten asper) of Kingskerswell, Devon
(Museum of Practical Geology, Jermyn Street, No. 997.)

1 Lamplugh and Kitchin, ‘ Mesozoic Rocks in the Coal Explorations in Kent’ (1911), p. 103.

ADDITIONS. 4.27

Cyerina Meyert, sp. nov. Plate LXII, figs. 2,-3.
[Omitted from Vol. II, p. 141.}

Description—Shell convex, oval, considerably inequilateral; anterior margin
rounded, passing gradually into the shghtly curved ventral margin; posterior
margin truncated; postero-dorsal margin convex. Umbones prominent, curved
inwards and forwards, with a rounded carina extending to the postero-ventral
angle, and limiting a flattened postero-dorsal region. Lunular region depressed.
Escutcheon long, deep, limited by a sharp carina. Ornamentation consists of con-
centric growth-rings. Length, 56mm.; height, 42 mm.

Affinities —This species shows some resemblance to C. beiivensis (leymerie),'
but is less elongate and much less convex.

T'ype.—In the Sedgwick Museum, Cambridge (C. J. A. Me¥er collection).

Distribution.—Lower Greensand (Peria-bed), of Sandown.

Cyprina? vectisna (Forbes), 1845. Plate LXII, fig. 4.
[Omitted from Vol. IT, p. 141.]

1845. Trnnina? vecrrana, 2. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 239,
pl. ii, fig. 2.
1854. Tennina vectrana, J. Morris. Cat. Brit. Foss., ed. 2, p. 227.
1865. “Tretia” vecriana, F. J. Pictet and G. Campiche. Terr. Crét. Ste. Croix
(Matér. Pal. Suisse, ser. 4), p. 141.
1871. Te~urna? vectrana (? Homatrna), F. Stoliczka. Paleont. Indica, Cret.
Fauna 8. India, vol. iii, p. 123.

Description —Shell triangular, moderately convex, with flattened sides, nearly
equilateral. Anterior margin rounded; ventral margin slightly curved; postero-
dorsal margin slightly convex, forming a rounded angle with the ventral margin.
Umbones prominent, sharp, slightly curved. Lunular region depressed. _ Escut-
cheon long, limited by a rounded carina extending from the umbones to the postero-
ventral extremity. Ornamentation consists of numerous strong concentric ribs,
separated by narrow grooves. Length, 25 mm.; height, 17 mm.

Affinities —This species shows some resemblance to C. cuneata, Sowerby, but
the shell is much more compressed, and possesses distinct concentric ribs. I am
not able to determine whether a postero-lateral tooth was present or not.

1 «Mem. Soe. géol. de France,’ vol. v (1842), p. 5, pl. v, fig.6. D’Orbigny, ‘ Pal. Frang. Terr. Crét.,’
vol. iii, pp. 98, 759, pl. cclxxi, and ‘ Prodr. de Pal.,’ vol. ii (1850), p. 77. Pictet and Campiche, ‘ Terr.
Crét. Ste. Croix’ (‘ Matér. Pal. Suisse,’ ser. 4, 1865), p. 212, pl. exiii, figs. 1, 2.

428 CRETACEOUS LAMELLIBRANCHIA.

Remarks.—The type cannot be found, but other specimens named by Forbes
are in the Museum of Practical Geology (Geological Society Collection, No, 2217).
Distribution.—Lower Greensand (Crackers) of Atherfield.

Unicarpium ? comMpressuM, sp. nov. Plate LXII, figs. 5, 6.

[Omitted from Vol. IT, p. 163. |

Deseription.—Shell convex, with flattened or slightly concave flanks, oval or
subquadrate, moderately or slightly mequilateral. Anterior margin rounded ;
posterior margin subtruncate, slightly oblique, curved; ventral margin nearly
straight and nearly parallel to the dorsal margin. _Umbones broad, close
together. A rounded carina extends from the umbo to the postero-ventral
extremity, limiting the compressed postero-dorsal region. External ligament broad.
Ornamentation consists of a few coarse somewhat irregular concentric ribs, which
are sometimes rugose, with finer ribs in the interspaces.

Measurements :

(1) (2)
Length . : : f ; : : . 40 : 32 mim.
Height . : : : ; : . 26 Zoe as
Thickness a : — 5,

(1, 2) Crackers, Athertield.
Affinities. —The hinge and interior of this species have not been seen, conse-
quently its generic position cannot at present be definitely determined, but it is

provisionally referred to Unicardium on account of its external resemblance to

some Jurassic species of that genus. U.? compressum is similar to some forms of

Mya vugosa, Romer,’ which has been referred to the genus Lucina by de Loriol

and Cotteau, to Mactromya by Agassiz, and to Unicardiwm by Zittel.
Type-—From Atherfield, in the Sedgwick Museum, Cambridge.
Distribution.—Lower Greensand (Crackers), of Atherfield. Atherfield Clay of

Dover Colliery.

Unicarpium ? Mainteancm (d’Orbigny), 1844. Plate LXII, figs. 7—9.
(Omitted from Vol. IL, p. 165).

1844. Carprum Mariiuranum, A. TiOnbaged SUREl ara Mecee nee mel ise
40, pl. celvi, figs. 7—12.

1 See especially de Loriol and Cotteau, ‘Mon. Paldéont. Géol. Portlandien de FYonne’ (1868),
p- 135, pl. ix, figs. 10, 11.

ADDITIONS. 4.29

1850, Carprum Maruieanvum, d’Orbigny. Prodr. de Pal., vol. ii, p. 162.
1866. — -- FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste.
Croix (Matér. Pal.
Suisse, ser. 4), p.
270.
1871. — — F. Stoliczka. Paleout. Indica, Cret. Fauna 8.
India, vol. ii, p. 213 (Levi-
. cardium).

Description.—Shell inflated, oval or subquadrate, longer than high, moderately
inequilateral. Anterior margin rounded, passing gradually into the slightly convex
ventral margin. Posterior margin high, subtruncate, forming an angle with the
straight postero-dorsal margin. Postero-dorsal part of shell compressed. Umbones
broad, curved forward. Ornamentation consists of concentric growth-lines and
fine radial ribs.

Measurements :

(1) (2) (3) (4)
Length : 31 30 29 24: mm.
Height ; A 27°5 27 26 ; 2
Thickness. 22 25 20 16

: F . *
Base of Chalk of (1) Beaminster, (2) Maiden Newton, (3) Cerne, (4) Titherleigh.

Remarks.—This species was referred to Cardium by d’Orbigny, but the shell
differs in form from that other Cretaceous species of that genus, and resembles
more nearly Unicardium. The hinge is not known satisfactorily, but internal casts
show indications of two cardinal teeth.

The ornamentation is often imperfectly preserved. I am indebted to M. de
Grossouvre for the opportunity of examining specimens from the Cenomanian of
Rouen.

Type.—From the Cenomanian of Rouen.

Distribution.—Base of the Chalk (zone of Schlanbachia varians) of Beaminster,
Cerne, Maiden Newton, Titherleigh and Chard.

Tennina ? pHAsEoLINA (Phillips), 1829. Plate LXII, fig. 10.

{Omitted from Vol. II, p. 177.]

1829. Mya puasrouina, J. Phillips. Geol. Yorks., p. 121 (p. 254, ed. 3), pl. ii,
fig. 13.
1850. Lavienon pHasgoutna, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 117.
1854. Mya puassourna, J. Morris. Cat. Brit. Foss., ed. 2, p. 212.
1870. Lavienon puHasrouina, F. Stoliczka. Paleont. Indica, Cret. Fauna S.
India, p. 111.

56

430 CRETACEOUS LAMELLIBRANCHIA.

Description.—Shell small, bean-shaped, convex, considerably inequilateral ;
posterior part higher than the anterior part. Anterior and posterior margins
rounded. Postero-dorsal margin slightly convex. Ventral margin with a slight
sinuosity. A rounded carina extends from the umbo towards the postero-ventral
extremity, and limits a compressed postero-dorsal area. Umbones broad, close
together.

Measurements :

Length . : . 85 mm. Height. : . 45 mm.

Affinities. —This species is more elongate and more convex than 1’. ? subphaseo-
lina (see below). No specimens having the shell preserved have been found.

l'ype.—A. specimen which is believed to be the type is in the York Museum.

Distribution.—Speeton Clay (zones of Belemnites jaculuim and B. brunsvicensis)
of Speeton.

TELLINA P SUBPHASEOLINA (d’Orbigny), 1850. Plate LXII, figs. 11, 12.
[Omitted from Vol. II, p. 177.)

1845. Lavicnon puasgouina, A. d’Orbigny. Pal. France. Terr. Crét., vol. iii, p.
407, pl. ceelxxvui, figs. 8—10.
1850. -- SUBPHASEOLINA, d’Orbigny. Prodr. de Pal., vol. ii, p. 136.
1865. TrLLina PHASEOLINA, F’. J. Pictet and G. Campiche. Terr. Crét. Ste.
Croix. (Matér. Pal. Suisse, ser.
4), p. 187, pl. eviii, fig. 10.
1870. LaviaNon sUBPHASEOLINA, F. Stoliczka. Palwont. Indica, Cret. Fauna
8. India, vol. ii, p. 111.
~- TELLINA PHASEOLINA, Stoliczka. Ibid., p. 125 (? Peronzxa).

Description.—Shell oval or subquadrate, compressed, considerably inequilateral,
posterior part higher than the anterior part. Postero-dorsal margin nearly straight ;
posterior margin curved; ventral margin with a shallow sinus due to a depression
on the sides of the shell; anterior margin rounded. Umbones small, close together ;
between the umbones and the postero-ventral extremity is the greatest convexity
of the shell.

Measurements :

Q) (2) (3)
Length : 5 : : ; 14 ; 14 : 12 mm.
Height ; ; ; : : 10 : hae Sher
Thickness . : — , 5 é A oe

(1—3) Gault, Folkestone.
Affinities —The hinge is not shown in any of the English specimens. Pictet
and Campiche saw casts of the teeth, and they refer the species without doubt to

ADDITIONS. ° 431

the genus Tellina. Externally, as was pointed out by Stoliezka, it resembles
Lepton.

Type.—From the Gault of Gérodot (Aube).

Distribution —Gault of Folkestone.

Cyrrimerta (CycLorisma) susmersa (Sowerby), 1836. Plate LXI, fig. 13.
[For references see Vol. IT, p. 192, foot-note. |

Description.—Shell oval, inequilateral, convex, with the postero-dorsal part
flattened and limited by a rounded carina passing from the umbo to the postero-
ventral angle. Antero-dorsal margin nearly straight. Anterior margin rounded,
passing gradually into the moderately convex ventral margin. Posterior margin
truncated. Postero-dorsal margin slightly curved. Umbones of moderate size,
with a shght forward curvature. Lunule limited by a faint groove. Escutcheon
elongate, bordered by a carina. Ornamentation consists of small concentric ribs.

Affinities.—The left valve, which is described above, was found by Mr. Jukes-
Browne in the Exeter Museum, and appears to be referable to Sowerby’s Venus
subinersa, the only apparent difference being in the greater length of the shell.

The hinge agrees closely with that of C. (Cyclorisma) parva (Sowerby) (p. 185).
Externally the shell is similar to C. (Cyclorisma) rotomagensis (d’Orbigny), but is
less convex, more elongated, more inequilateral, with the forward curvature of
the umbones more marked and the posterior margin more distinctly truncated.

Distribution —Upper Greensand (zone of Schlanbachia rostrata) of Blackdown.

Genus—Tares, Megerle von Mihlfeld, 1811.
[Omitted from Vol. II, p. 194.]
Sub-genus—lcanona, Ff. Stoliczka, 1870.
(Paleont. Indica, Cret. Fauna 8. India, vol. iii, p. 145.)
Tares (Icanorta) sp. Plate LXII, fig. 14.

Description.—Shell elongate-oval, very inequilateral, compressed, anterior and
posterior ends rounded. Ventral margin convex ; postero-dorsal margin nearly
straight. Umbones inconspicuous. Ornamentation consists of numerous, close,
radial ribs which are indistinct on the anterior part of the valve, and become

stronger and more widely separated on the posterior part, where a small rib may
occur between two larger ones. Length (approximate) 55 mm., height 26 mm.

432 CRETACEOUS LAMELLIBRANCHIA.

Affinities—Only two right valves of this species have been seen. They
resemble closely Capsa elegans, d’ Orbigny,' but the ribs on the posterior part of the
sheH are more numerous and less coarse.

Distribution.—Upper Greensand (zone of Schleubachia rostrata) of Blackdown
and Haldon.

LEproso.en ? rectaANGULARIS (Woods), 1897. Plate LXII, figs. 15—17.

[Omitted from Vol. II, p. 221.]

1897, Trapezium recraneutareE, H. Woods. Quart. Journ. Geol. Soe., vol. liii,
p. 392, pl. xxviii, figs. 11, 12.

Description.—Shell more or less oblong, very inequilateral, moderately convex,
with flattened or slightly concave sides. Anterior part not so high as the posterior
part. Postero-dorsal margin nearly straight and nearly parallel to the ventral
margin; anterior margin rounded ; posterior margin truncated, slightly convex or
nearly straight, and almost at right angles to the postero-dorsal margin. Umbones
inconspicuous, with a carina extending in a curve to the postero-ventral angle, and
limiting a triangular postero-dorsal area. A strong internal ridge extends from
the umbo towards the opposite ventral margin. Length 19 mm., height 11 mm.

Ajjinities.—A similar species has been referred doubtfully by Weller? to
Leptosolen. Modiola tetragona, Reuss,’ also shows some resemblance to the English
species. ‘The hinge is not shown in any of the specimens, and the generic position
must be regarded as uncertain.

T'ype.—In the Sedgwick Museum, Cambridge.

Distribution.—Chalk Rock of Cuckhamsley, Berkshire.

Vol. I, page 230, line 5 from the bottom, for “ varians” read “ rostrata.”

TuraciaP Gracitis (Sowerby), 1836. Plate LXII, figs. 18, 19.

{Omitted from Vol. I, p. 244. ]

1836, Psammosra? Graciuis, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv,
pp. 242, 341, pl. xvi, fig. 12.

1850. Tenura e@raciiis, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 159.

1854, Psammosra araciis, J. Morris. Cat. Brit. Foss., ed. 2, p. 222.

1 «Pal. Fiane. Terr. Cret.,’ vol. iii (1845), p. 423, pl. ecelxxxi, figs. 1, 2.
* «Cret. Paleont. New Jersey’ (1907), p. 626, pl. Ixx, fig. 29.
’ ‘Die Verstein. der béhm. Kreideformat.,’ pt. 2 (1846), p. 15, pl. xxxiii, fig. 6,

ADDITIONS. 435

1865. Trnuma eracixis, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste.

Croix (Matér Pal. Suisse,
ser. 4), p. 188.
? 1868. — — A. Briart and F. L. Cornet. Meule de Bracquegnies
(Mém. cour. et Mém. des Sav.
étrangers, vol. xxxiv), p. 80,
pl. vii, fig. 19, 20.
1870. — — F. Stoliczka. Paleont. Indica, Cret. Fauna S. India,
vol. iii, p. 123.

Description.—Shell elongate-oval, moderately convex, slightly imequivalve and
inequilateral. Anterior margin rounded. Ventral margin slightly or moderately
convex, and forming an acute angle with obliquely truncated posterior margin.
Umbones incurved. A sharp carina extends in a curve from the umbo to the
postero-ventral angle, and cuts off a flat or slightly concave postero-dorsal area.
Ornamentation consists of concentric ribs, which are less numerous but stronger on
the anterior part of the shell and the postero-dorsal area than elsewhere.

Measurements :

(1) (2)
Length . : . ? 14 : 8 mm.
Height. : F 6 3 A.

33

(1, 2) Blackdown.
Affinities.—This species resembles T'hracia elegans (d’Orbigny)' but possesses
stronger concentric ribs. Its generic position cannot be determined definitely
since only a few specimens have been seen, none of which shows the hinge or
interior.
Type.—The type from Blackdown cannot be found.
Distribution.—Upper Greensand (zone of Schlenbachia rostrata) of Blackdown.

Tnoceramus tuBercutarus, Woods. [See Vol. II, p. 302.}

An example of this species has been found in the zone of Actinovamae
quadratus of Kast Harnham, Salisbury, by Dr. Blackmore.

Inoceramus INTERMEDIUS, Sowerby.
[Loudon’s ‘ Mag. Nat. Hist.,’ vol. ii (1829), p. 296, fig. 83. }

The figure given by Sowerby of a specimen from Norfolk appears to have
been overlooked by previous writers; it probably represents a large form of
I. Lamarcki var. apicalis.

1 « Pal. Frang. Terr. Crét.,’ vol. iii (1845),%p. 386, pl. ccelxxiii, figs. 3—5.

43.4, CRETACEOUS LAMELLIBRANCHIA.

I.—DISTRIBUTION OF THE LOWER CRETACEOUS SPECIES IN ENGLAND.

The genera are arranged in the order of the classification followed in this work. The species of
each genus or subgenus are in alphabetical order. The stratigraphical divisions are those adopted im

the ‘ Memoirs of the Geological Survey.’

Ys i c -
Yorkshire, Lincolnshire, | C@™@>tidge- | rho Weald and
N S shire to WH:
| orfolk. Wiltshire, | [sle of Wight. |
| | | i : liars 5
8 as ai | ¢ gies |
Sle aie Pa| 3] | eHlBel
Volume SI d| n ” ss O44 Ro} Ee ap
Genus and Species. and EIS = = 2 Za| Usd Pa = ese
Pace agile 2 = |° Ae | Se] 3 ieegise
age. | ga) s = = Digit ay es | ace S ilaeklog
ee 3 S2/ ssl Gs Anim | wey I
PRs Ss |S8\54138| 382 gE\o®
melm im |MS|AB] BS) BETS lak 2 |
dolwdlagilas|On| oe | onl] & |s2\35]
BRISSISE(SS|L4] 2H | 2h] S | oleae]
S8lofloslo2/S8] 2a) 28] & |ae/fu|
eaep\asliae S|)E OL Ea | 2a] & | es ts |
BE\SS/SSiSE/S2] 63 | 88) S Feiss
AAINSINKSINS|AFPIT HE | Ae 4 Dama
| |
|NucULANA
scapha (d’ Orb.) I, 3 x x
Seeleyi (Gaird.) ......ccnssescnennere ene [5 x
spathulata (Forb.) .. Br reo ee el ? xg ||
speetonensis, WiO0dS ses es toceraeanane I,3 x
subrecurva (Piill.)............ Aenp ene I x
|NucuLa
Lamplughi, Woods JT, 14 x
| Meyeri, Gard. . os ee Re ee I, 15 ae x
plan: ita, Desh. ........ I, 12 ee fh x 1x
sp. [Cornueliana, ‘Gard. non d’ Orb. ; I, 15 x x
sp. [simplex, Gard. non Desh.)...... I, 14 x
ANOMIA
GOMVEXA IS OWs ncriecGice . Anise mean ane 29 x
levigata, Sow....... eee 2 Fee || pe es) x x
pseudoradi: ita, a Orbe: ey x x |
|
ARCA
Garteronind Orb: essen veers I, 3: x x
Mupmmiana sd Onb esses eal